Chapter 9 Chemical Quantities Answers

Problem ane

Although mass is a property of thing we can conveniently measure out in the laboratory, the coefficients of a counterbalanced chemical equation are not straight interpreted on the basis of mass. Explain why.

Dr. Satish I.

Numerade Educator

Problem 2

Explicate why, in the balanced chemical equation $\mathrm{C}+\mathrm{O}_{2} \rightarrow \mathrm{CO}_{2},$ we know that i $\mathrm{g}$ of $\mathrm{C}$ will $\mathrm{not}$ react exactly with i $\mathrm{one thousand}$ of $\mathrm{O}_{two}$ .

Vasu M.

Numerade Educator

Problem 3

For each of the post-obit reactions, requite the balanced equation for the reaction and state the meaning of the equation in terms of numbers of individual molecules and in terms of moles of molecules.
a. $\mathrm{NO}(yard)+\mathrm{O}_{2}(g) \rightarrow \mathrm{NO}_{2}(chiliad)$
b. $\mathrm{AgC}_{2} \mathrm{H}_{iii} \mathrm{O}_{2}(a q)+\mathrm{CuSO}_{iv}(a q) \rightarrow$
$\quad \mathrm{Ag}_{2} \mathrm{SO}_{4}(due south)+\mathrm{Cu}\left(\mathrm{C}_{2} \mathrm{H}_{3} \mathrm{O}_{2}\right)_{2}(a q)$
c. $\mathrm{PCl}_{3}(l)+\mathrm{H}_{2} \mathrm{O}(l) \rightarrow \mathrm{H}_{3} \mathrm{PO}_{3}(l)+\mathrm{HCl}(g)$
d. $\mathrm{C}_{2} \mathrm{H}_{half dozen}(1000)+\mathrm{Cl}_{2}(g) \rightarrow \mathrm{C}_{ii} \mathrm{H}_{5} \mathrm{Cl}(g)+\mathrm{HCl}(g)$

Rachel Five.

Numerade Educator

Trouble 4

For each of the post-obit reactions, give the balanced chemical equation for the reaction and state the meaning of the equation in terms of individual molecules and in terms of moles of molecules.
a. $\mathrm{MnO}_{two}(s)+\mathrm{Al}(due south) \rightarrow \mathrm{Mn}(s)+\mathrm{Al}_{2} \mathrm{O}_{3}(s)$
b. $\mathrm{B}_{two} \mathrm{O}_{3}(s)+\mathrm{CaF}_{two}(s) \rightarrow \mathrm{BF}_{iii}(thou)+\mathrm{CaO}(southward)$
c. $\mathrm{NO}_{2}(m)+\mathrm{H}_{2} \mathrm{O}(l) \rightarrow \mathrm{HNO}_{3}(a q)+\mathrm{NO}(g)$
d. $\mathrm{C}_{6} \mathrm{H}_{6}(l)+\mathrm{H}_{2}(1000) \rightarrow \mathrm{C}_{six} \mathrm{H}_{12}(fifty)$

Rachel 5.

Numerade Educator

Trouble five

True or false? For the reaction represented past the chemical equation
$$2 \mathrm{H}_{ii} \mathrm{O}_{2}(a q) \rightarrow two \mathrm{H}_{2} \mathrm{O}(l)+\mathrm{O}_{2}(g)$$
if ii.0 $\mathrm{grand}$ of hydrogen peroxide decomposes, then two.0 $\mathrm{g}$ of water and 1.0 $\mathrm{thousand}$ of oxygen gas will exist produced.

Rachel V.

Numerade Educator

Problem six

Consider the balanced equation
$$\mathrm{CH}_{four}(g)+ii \mathrm{O}_{2}(k) \rightarrow \mathrm{CO}_{two}(g)+ii \mathrm{H}_{2} \mathrm{O}(k)$$
What is the mole ratio that would enable you to calculate the number of moles of oxygen needed to react exactly with a given number of moles of $\mathrm{CH}_{4}(k) ?$ What mole ratios would you use to summate how many moles of each product form from a given number of moles of $\mathrm{CH}_{four} ?$

Rachel V.

Numerade Educator

Problem 7

Consider the unbalanced chemical equation
$$\mathrm{Ag}(south)+\mathrm{H}_{2} \mathrm{S}(g) \rightarrow \mathrm{Ag}_{2} \mathrm{S}(s)+\mathrm{H}_{two}(one thousand)$$
Balance the equation. Identify the mole ratios that yous would use to calculate the number of moles of each product that would class for a given number of moles of argent reacting.

Rachel V.

Numerade Educator

Problem 8

For each of the following unbalanced chemical equations, calculate how many moles of each production would be produced by the complete conversion of 0.125 mol of the reactant indicated in boldface. State clearly the mole ratio used for the conversion.
a. $\mathbf{F} \mathrm{e} \mathbf{O}(s)+\mathrm{C}(s) \rightarrow \mathrm{Fe}(l)+\mathrm{CO}_{ii}(thou)$
b. $\mathrm{Cl}_{2}(thousand)+\mathbf{Thousand I}(a q) \rightarrow \mathrm{KCl}(a q)+\mathrm{I}_{2}(s)$
c. $\mathbf{N a}_{2} \mathbf{B}_{4} \mathbf{O}_{vii}(southward)+\mathrm{H}_{2} \mathrm{And then}_{4}(a q)+\mathrm{H}_{2} \mathrm{O}(l)-$
$\quad \mathrm{H}_{3} \mathrm{BO}_{iii}(due south)+\mathrm{Na}_{2} \mathrm{SO}_{iv}(a q)$
d. $\mathbf{C a C}_{ii}(due south)+\mathrm{H}_{two} \mathrm{O}(l) \rightarrow$
$\quad \mathrm{Ca}(\mathrm{OH})_{ii}(s)+\mathrm{C}_{2} \mathrm{H}_{2}(g)$

Rachel V.

Numerade Educator

Trouble ix

For each of the following balanced chemic equations, calculate how many moles and how many grams of each production would be produced past the complete conversion of 0.50 mol of the reactant indicated in boldface. State clearly the mole ratio used for each conversion.
a. $\mathbf{N H}_{3}(g)+\mathrm{HCl}(1000) \rightarrow \mathrm{NH}_{iv} \mathrm{Cl}(s)$
b. $\mathrm{CH}_{4}(g)+4 \mathbf{S}(south) \rightarrow \mathrm{CS}_{two}(fifty)+2 \mathrm{H}_{2} \mathrm{S}(yard)$
c. $\mathbf{P C fifty}_{iii}(fifty)+3 \mathrm{H}_{2} \mathrm{O}(l) \rightarrow \mathrm{H}_{3} \mathrm{PO}_{3}(a q)+3 \mathrm{HCl}(a q)$
d. $\mathrm{NaOH}(due south)+\mathrm{CO}_{ii}(g) \rightarrow \mathrm{NaHCO}_{3}(south)$

Rachel V.

Numerade Educator

Problem 10

For each of the following unbalanced equations bespeak how many moles of the starting time product are produced if 0.625 mol of the second product forms. State clearly the mole ratio used for each conversion.
a. $\mathrm{KO}_{2}(s)+\mathrm{H}_{2} \mathrm{O}(l) \rightarrow \mathrm{O}_{2}(1000)+\mathrm{KOH}(southward)$
b. $\mathrm{SeO}_{2}(g)+\mathrm{H}_{2} \mathrm{Se}(1000) \rightarrow \operatorname{Se}(s)+\mathrm{H}_{2} \mathrm{O}(g)$
c. $\mathrm{CH}_{3} \mathrm{CH}_{two} \mathrm{OH}(l)+\mathrm{O}_{2}(yard) \rightarrow$
$\quad \mathrm{CH}_{three} \mathrm{CHO}(a q)+\mathrm{H}_{2} \mathrm{O}(50)$
d. $\mathrm{Iron}_{2} \mathrm{O}_{three}(southward)+\mathrm{Al}(due south) \rightarrow \mathrm{Fe}(l)+\mathrm{Al}_{2} \mathrm{O}_{three}(s)$

Rachel Five.

Numerade Educator

Problem 11

What quantity serves as the conversion factor betwixt the mass of a sample and the number of moles the sample contains?

Rachel 5.

Numerade Educator

Problem 12

What does it mean to say that the balanced chemical equation for a reaction describes the stoichiometry of the reaction?

Rachel Five.

Numerade Educator

Problem 13

Using the average atomic masses given inside the forepart cover of the text, calculate the number of moles of each substance contained in the following masses.
a. $2.01 \times 10^{-two} \mathrm{g}$ of silverish
b. 45.two $\mathrm{mg}$ of ammonium sulfide
c. 61.7 \mug of uranium
d. 5.23 $\mathrm{kg}$ of sulfur dioxide
e. 272 $\mathrm{g}$ of atomic number 26(Three) nitrate
f. 12.vii $\mathrm{mg}$ of fe(2) sulfate
yard. $six.91 \times 10^{3} \mathrm{g}$ of lithium hydroxide

Rachel V.

Numerade Educator

Problem xiv

Using the boilerplate atomic masses given within the front comprehend of the text, calculate the mass in grams of each of the following samples.
a. $2.21 \times 10^{-4}$ mol of calcium carbonate
b. two.75 mol of helium
c. 0.00975 mol of oxygen gas
d. $7.21 \times x^{-3}$ mol of carbon dioxide
eastward. 0.835 mol of fe(Two) sulfide
f. 4.01 mol of potassium hydroxide
m. 0.0219 mol of hydrogen gas

Rachel Five.

Numerade Educator

Problem xv

For each of the following unbalanced equations, calculate how many moles of the 2nd reactant would be required to react completely with exactly 25.0 thousand of the first reactant. Betoken conspicuously the mole ratio used for each conversion.
a. $\mathrm{Mg}(southward)+\mathrm{CuCl}_{2}(a q) \rightarrow \mathrm{MgCl}_{two}(a q)+\mathrm{Cu}(due south)$
b. $\mathrm{AgNO}_{3}(a q)+\mathrm{NiCl}_{2}(a q) \rightarrow$
$\quad \mathrm{AgCl}(s)+\mathrm{Ni}\left(\mathrm{NO}_{3}\correct)_{two}(a q)$
c. NaHSO $_{3}(a q)+\mathrm{NaOH}(a q) \rightarrow$
$\quad \mathrm{Na}_{2} \mathrm{SO}_{iii}(a q)+\mathrm{H}_{two} \mathrm{O}(50)$
d. $\mathrm{KHCO}_{3}(a q)+\mathrm{HCl}(a q) \rightarrow$
$\quad \mathrm{KCl}(a q)+\mathrm{H}_{2} \mathrm{O}(l)+\mathrm{CO}_{ii}(thousand)$

Rachel V.

Numerade Educator

Problem xvi

For each of the post-obit unbalanced equations, summate how many milligrams of each product would be produced by consummate reaction of 10.0 mg of the reactant indicated in boldface. Signal clearly the mole ratio used for the conversion.
a. $\mathrm{FeSO}_{4}(a q)+\mathrm{K}_{two} \mathrm{CO}_{3}(a q) \rightarrow$
$\quad \mathrm{FeCO}_{3}(due south)+\mathrm{Grand}_{2} \mathrm{And then}_{4}(a q)$
b. $\mathbf{C} \mathbf{r}(s)+\operatorname{SnCl}_{4}(fifty) \rightarrow \mathrm{CrCl}_{3}(south)+\operatorname{Sn}(s)$
c. $\mathrm{Fe}(southward)+\mathbf{S}_{\mathbf{one thousand}}(s) \rightarrow \mathrm{Fe}_{2} \mathrm{S}_{three}(south)$
d. $\mathrm{Ag}(s)+\mathbf{H N O}_{iii}(a q) \rightarrow$
$\quad \mathrm{AgNO}_{3}(a q)+\mathrm{H}_{2} \mathrm{O}(l)+\mathrm{NO}(g)$

Rachel V.

Numerade Educator

Trouble 17

Although mixtures of hydrogen and oxygen are highly explosive, pure elemental hydrogen gas itself burns quietly in air with a pale blue flame, producing h2o vapor.
$$2 \mathrm{H}_{2}(g)+\mathrm{O}_{2}(g) \rightarrow two \mathrm{H}_{2} \mathrm{O}(g)$$
Calculate the mass (in grams) of h2o vapor produced when 56.0 $\mathrm{g}$ of pure hydrogen gas burns in air.

Rachel V.

Numerade Educator

Problem 18

Given the information in Problem 17, calculate the mass of oxygen gas that would be necessary to burn 0.0275 mol of hydrogen gas.

Rachel Five.

Numerade Educator

Problem 19

When elemental carbon is burned in the open up atmosphere, with plenty of oxygen gas present, the product is carbon dioxide.
$$C(southward)+\mathrm{O}_{2}(g) \rightarrow \mathrm{CO}_{2}(grand)$$
However, when the amount of oxygen present during the called-for of the carbon is restricted, carbon monoxide is more likely to result.
$$two \mathrm{C}(s)+\mathrm{O}_{ii}(g) \rightarrow two \mathrm{CO}(k)$$
What mass of each product is expected when a $five.00-\mathrm{yard}$ sample of pure carbon is burned under each of these conditions?

Rachel V.

Numerade Educator

Problem xx

Although we usually think of substances equally "burning" simply in oxygen gas, the process of rapid oxidation to produce a flame may besides accept place in other strongly oxidizing gases. For case, when atomic number 26 is heated and placed in pure chlorine gas, the iron "burns" according to the following (unbalanced) reaction:
$$\mathrm{Fe}(s)+\mathrm{Cl}_{two}(g) \rightarrow \mathrm{FeCl}_{three}(due south)$$
How many milligrams of iron(II) chloride consequence when 15.5 $\mathrm{mg}$ of atomic number 26 is reacted with an backlog of chlorine gas?

Rachel V.

Numerade Educator

Problem 21

Small quantities of oxygen gas tin can be generated in the laboratory by the decomposition of hydrogen peroxide. The unbalanced equation
for the reaction is
$$\mathrm{H}_{2} \mathrm{O}_{2}(a q) \rightarrow \mathrm{H}_{2} \mathrm{O}(50)+\mathrm{O}_{ii}(1000)$$
Summate the mass of oxygen produced when 10.00 chiliad of hydrogen peroxide decomposes.

Rachel V.

Numerade Educator

Trouble 22

An introductory chemistry experiment involves heating finely divided copper metallic with sulfur to determine the proportions in which the elements react to class copper(Two) sulfide. The experiment works well because any excess sulfur beyond that required to react with the copper may be simply boiled away from the reaction container.
$$\mathrm{Cu}(s)+\mathrm{Due south}(s) \rightarrow \operatorname{CuS}(s)$$
If 1.25 $\mathrm{g}$ of copper is heated with an excess of sulfur, how many grams of sulfur will react?

Rachel V.

Numerade Educator

Problem 23

Ammonium nitrate has been used every bit a loftier explosive because it is unstable and decomposes into several gaseous substances. The rapid expansion of the gaseous substances produces the explosive strength.
$$\mathrm{NH}_{four} \mathrm{NO}_{three}(due south) \rightarrow \mathrm{N}_{2}(thousand)+\mathrm{O}_{2}(chiliad)+\mathrm{H}_{ii} \mathrm{O}(g)$$
Calculate the mass of each product gas if ane.25 $\mathrm{yard}$ of ammonium nitrate reacts.

Rachel V.

Numerade Educator

Trouble 24

Magnesium metal burns in oxygen with an intensely bright white flame. The balanced equation for this reaction is
$$ii \mathrm{Mg}(s)+\mathrm{O}_{2}(g) \rightarrow 2 \mathrm{MgO}(\mathrm{s})$$
How many grams of $\mathrm{MgO}(southward)$ are produced by complete reaction of 1.25 $\mathrm{chiliad}$ of magnesium metal?

Rachel V.

Numerade Educator

Trouble 25

If chlorine gas is bubbled through a potassium iodide solution, elemental iodine is produced. The unbalanced equation is
$$\mathrm{Cl}_{two}(thousand)+\mathrm{KI}(a q) \rightarrow \mathrm{I}_{2}(s)+\mathrm{KCl}(a q)$$
Calculate the mass of iodine produced when $iv.fifty \times 10^{3} \mathrm{1000}$ of chlorine gas is bubbled through an excess amount of potassium iodide solution.

Rachel V.

Numerade Educator

Problem 26

Elemental fluorine and chlorine gases are very reactive. For case, they react with each other to course chlorine monofluoride.
$$\mathrm{Cl}_{2}(g)+\mathrm{F}_{2}(g) \rightarrow 2 \mathrm{ClF}(g)$$
Calculate the mass of chlorine gas required to produce $5.00 \times 10^{-3} \mathrm{grand}$ of chlorine monofluoride given an excess of fluorine gas.

Rachel Five.

Numerade Educator

Trouble 27

Both propane $\left(\mathrm{C}_{3} \mathrm{H}_{8}\right)$ and butane $\left(\mathrm{C}_{4} \mathrm{H}_{10}\right)$ react with oxygen gas to form carbon dioxide and water. If you accept equal masses of each, which will require a greater mass of oxygen to react?

Rachel 5.

Numerade Educator

Problem 28

Methane $\left(\mathrm{CH}_{4}\right)$ reacts with oxygen in the air to produce carbon dioxide and water. Ammonia $\left(\mathrm{NH}_{3}\right)$ reacts with oxygen in the air to produce nitrogen monoxide and water. What mass of ammonia is needed to react with backlog oxygen to produce the same amount of water as ane.00 $\mathrm{g}$ of methane reacting with excess oxygen?

Rachel Five.

Numerade Educator

Problem 29

What is the limiting reactant for a process? Why does a reaction terminate when the limiting reactant is consumed, even though at that place may exist plenty of the other reactants nowadays?

Rachel 5.

Numerade Educator

Problem 30

Nitrogen $(\mathrm{Due north}_{2})$ and hydrogen $(\mathrm{H}_{2})$. react to form ammonia $(\mathrm{NH}_{3})$. Consider the mixture of $\mathrm{N}_{ii}$ and $\mathrm{H}_{2}$ in a closed container as illustrated beneath:
IMAGE IS Non Bachelor TO Copy
Assuming the reaction goes to completion, depict a representation of the product mixture. Explicate how you arrived at this representation.

Rachel Five.

Numerade Educator

Problem 31

Explain how one determines which reactant in a process is the limiting reactant. Does this depend but on the masses of the reactant present? Is the mole ratio in which the reactants combine involved?

Rachel Five.

Numerade Educator

Problem 32

How does the maximum yield of products for a reaction depend on the limiting reactant?

Rachel Five.

Numerade Educator

Problem 33

What does it mean to say that a reactant is present "in excess" in a procedure? Can the limiting reactant be nowadays in backlog? Does the presence of an excess of a reactant bear upon the mass of products expected for a reaction?

Rachel Five.

Numerade Educator

Problem 34

For each of the following unbalanced chemical equations, suppose that exactly xv.0 g of each reactant is taken. Determine which reactant is limiting, and calculate what mass of each product is expected. (Presume that the limiting reactant is completely consumed.)
a. $\mathrm{Al}(s)+\mathrm{HCl}(a q) \rightarrow \mathrm{AlCl}_{3}(a q)+\mathrm{H}_{2}(yard)$
b. $\mathrm{NaOH}(a q)+\mathrm{CO}_{2}(k) \rightarrow$
$\quad \mathrm{Na}_{two} \mathrm{CO}_{iii}(a q)+\mathrm{H}_{2} \mathrm{O}(50)$
c. Pb(NO) $_{3}(a q)+\operatorname{HCl}(a q) \rightarrow$
$\quad \operatorname{PbCl}_{2}(due south)+\mathrm{HNO}_{iii}(a q)$
d. $\mathrm{Thousand}(south)+\mathrm{I}_{2}(s) \rightarrow \mathrm{KI}(southward)$

Rachel 5.

Numerade Educator

Problem 35

For each of the following unbalanced chemical equations, suppose that exactly l.0 g of each reactant is taken. Make up one's mind which reactant is limiting, and calculate what mass of the production in boldface is expected. (Presume that the limiting reactant is completely consumed.)
a. $\mathrm{NH}_{3}(g)+\mathrm{Na}(s) \rightarrow \mathbf{N} \mathbf{a} \mathbf{N} \mathbf{H}_{ii}(south)+\mathrm{H}_{2}(chiliad)$
b. $\mathrm{BaCl}_{2}(a q)+\mathrm{Na}_{2} \mathrm{Then}_{4}(a q) \rightarrow$
$\quad \mathbf{B a Southward O}_{4}(s)+\mathrm{NaCl}(a q)$
c. $\mathrm{SO}_{ii}(g)+\mathrm{NaOH}(south) \rightarrow \mathbf{North a}_{two} \mathbf{Southward O}_{3}(s)+\mathrm{H}_{two} \mathrm{O}(l)$
d. $\mathrm{Al}(s)+\mathrm{H}_{two} \mathrm{SO}_{iv}(a q) \rightarrow \mathbf{A} \mathbf{l}_{2}\left(\mathbf{S} \mathbf{O}_{4}\right)_{3}(s)+\mathrm{H}_{2}(g)$

Rachel V.

Numerade Educator

Problem 36

For each of the following unbalanced chemic equations, suppose that 10.0 mg of each reactant is taken. Show past adding which reactant is limiting. Calculate the mass of each product that is expected.
a. $\mathrm{CO}(g)+\mathrm{H}_{two}(m) \rightarrow \mathrm{CH}_{3} \mathrm{OH}(l)$
b. $\mathrm{Al}(s)+\mathrm{I}_{2}(s) \rightarrow \mathrm{AlI}_{3}(s)$
c. $\mathrm{Ca}(\mathrm{OH})_{2}(a q)+\mathrm{HBr}(a q) \rightarrow$
$\quad \mathrm{CaBr}_{2}(a q)+\mathrm{H}_{ii} \mathrm{O}(fifty)$
d. $\mathrm{Cr}(s)+\mathrm{H}_{3} \mathrm{PO}_{4}(a q) \rightarrow \mathrm{CrPO}_{4}(due south)+\mathrm{H}_{2}(g)$

Rachel V.

Numerade Educator

Problem 37

The more reactive halogen elements are able to replace the less reactive halogens from their compounds.
$$\mathrm{Cl}_{2}(g)+\mathrm{NaI}(a q) \rightarrow \mathrm{NaCl}(a q)+\mathrm{I}_{ii}(s)$$
$$\mathrm{Br}_{ii}(50)+\mathrm{NaI}(a q) \rightarrow \operatorname{NaBr}(a q)+\mathrm{I}_{2}(s)$$
Suppose that separate solutions, each containing 25.0 $\mathrm{g}$ of Nal, are bachelor. If 5.00 $\mathrm{chiliad}$ of $\mathrm{Cl}_{2}$ gas is bubbled into one NaI solution, and 5.00 $\mathrm{g}$ of liquid bromine is added to the other, summate the number of grams of elemental iodine produced in each case.

Rachel 5.

Numerade Educator

Problem 38

If steel wool (atomic number 26) is heated until it glows and is placed in a canteen containing pure oxygen, the iron reacts spectacularly to produce iron(2) oxide.
$$\mathrm{Fe}(due south)+\mathrm{O}_{two}(grand) \rightarrow \mathrm{Fe}_{2} \mathrm{O}_{3}(s)$$
If 1.25 g of iron is heated and placed in a canteen containing 0.0204 mol of oxygen gas, what mass of iron(III) oxide is produced?

Rachel V.

Numerade Educator

Problem 39

One method for chemical analysis involves finding some reagent that will precipitate the species of interest. The mass of the precipitate is then used to determine what mass of the species of interest was present in the original sample. For case, calcium ion tin can be precipitated from solution by addition of sodium oxalate. The balanced equation is
$$\mathrm{Ca}^{2+}(a q)+\mathrm{Na}_{2} \mathrm{C}_{2} \mathrm{O}_{4}(a q) \rightarrow$$
$$\quad \mathrm{CaC}_{2} \mathrm{O}_{4}(south)+2 \mathrm{Na}^{+}(a q)$$
Suppose that a solution is known to contain approximately 15 g of calcium ion. Show by calculation whether the addition of a solution containing 15 g of sodium oxalate will precipitate all of the calcium from the sample.

Rachel V.

Numerade Educator

Problem 40

What is the actual yield of a reaction? What is the per centum yield of a reaction? How practice the actual yield and the percent yield differ from the theoretical yield?

Rachel 5.

Numerade Educator

Problem 41

The text explains that 1 reason why the actual yield for a reaction may exist less than the theoretical yield is side reactions. Suggest some other reasons why the percentage yield for a reaction might not be 100%.

Rachel Five.

Numerade Educator

Problem 42

According to his prelaboratory theoretical yield calculations, a student's experiment should have produced 1.44 chiliad of magnesium oxide. When he weighed his product subsequently reaction, only ane.23 g of magnesium oxide was present. What is the educatee'due south percent yield?

Jennifer H.

Numerade Educator

Problem 43

The compound sodium thiosulfate pentahydrate, $\mathrm{Na}_{ii} \mathrm{Southward}_{2} \mathrm{O}_{3} \cdot v \mathrm{H}_{2} \mathrm{O},$ is important commercially to the photography business every bit "hypo," because it has the ability to dissolve unreacted silver salts from photographic film during development. Sodium thiosulfate pentahydrate can be produced by boiling elemental sulfur in an aqueous solution of sodium sulfite.
$$\mathrm{Due south}_{\mathrm{thousand}}(s)+\mathrm{Na}_{2} \mathrm{And so}_{3}(a q)+\mathrm{H}_{2} \mathrm{O}(fifty) \rightarrow$$
$$\quad \mathrm{Na}_{ii} \mathrm{South}_{2} \mathrm{O}_{three} \cdot five \mathrm{H}_{ii} \mathrm{O}(s)(\text { unbalanced })$$
What is the theoretical yield of sodium thiosulfate pentahydrate when 3.25 one thousand of sulfur is boiled with xiii.1 one thousand of sodium sulfite? Sodium thiosulfate pentahydrate is very soluble in water. What is the pct yield of the synthesis if a pupil doing this experiment is able to isolate (collect) only v.26 g of the product?

Rachel V.

Numerade Educator

Problem 44

Brine metal hydroxides are sometimes used to "scrub" excess carbon dioxide from the air in airtight spaces (such equally submarines and spacecraft). For case, lithium hydroxide reacts with carbon dioxide according to the unbalanced chemical equation
$$\mathrm{LiOH}(due south)+\mathrm{CO}_{two}(g) \rightarrow \mathrm{Li}_{2} \mathrm{CO}_{3}(southward)+\mathrm{H}_{ii} \mathrm{O}(yard)$$
Suppose that a lithium hydroxide cannister contains 155 $\mathrm{g}$ of $\mathrm{LiOH}(s) .$ What mass of $\mathrm{CO}_{2}(g)$ will the cannister be able to absorb? If information technology is establish that after 24 hours of apply the cannister has absorbed 102 $\mathrm{k}$ of carbon dioxide, what percentage of its capacity has been reached?

Rachel 5.

Numerade Educator

Trouble 45

Although they were formerly called the inert gases, at least the heavier elements of Grouping eight do form relatively stable compounds. For example, xenon combines directly with elemental fluorine at elevated temperatures in the presence of a nickel catalyst.
$$\mathrm{Xe}(chiliad)+2 \mathrm{F}_{ii}(1000) \rightarrow \mathrm{XeF}_{4}(southward)$$
What is the theoretical mass of xenon tetrafluoride that should form when 130 . $\mathrm{one thousand}$ of xenon is reacted with $100 . \mathrm{g}$ of $\mathrm{F}_{2} ?$ What is the percent yield if only 145 $\mathrm{g}$ of $\mathrm{XeF}_{iv}$ is actually isolated?

Rachel 5.

Numerade Educator

Problem 46

Anhydrous calcium chloride, $\mathrm{CaCl}_{two}$ , is frequently used in the laboratory as a drying agent for solvents considering information technology absorbs half dozen $\mathrm{mol}$ of h2o molecules for every mole of $\mathrm{CaCl}_{2}$, used (forming a stable solid hydrated salt, $\mathrm{CaCl}_{2} \cdot half-dozen \mathrm{H}_{2}$ ). Calcium chloride is typically prepared by treating calcium carbonate with hydrogen chloride gas.
$$\mathrm{CaCO}_{3}(s)+2 \mathrm{HCl}(1000) \rightarrow$$
$$\qquad \mathrm{CaCl}_{2}(due south)+\mathrm{CO}_{2}(yard)+\mathrm{H}_{two} \mathrm{O}(chiliad)$$
A big corporeality of heat is generated by this reaction, so the water produced from the reaction is usually driven off as steam. Some liquid h2o may remain, however, and it may dissolve some of the desired calcium chloride. What is the percent yield if 155 g of calcium carbonate is treated with 250 . of anhydrous hydrogen chloride and only 142 thou of $\mathrm{CaCl}_{2}$ is obtained?

Rachel 5.

Numerade Educator

Trouble 47

One process for the commercial product of blistering soda (sodium hydrogen carbonate) involves the following reaction, in which the carbon dioxide is used in its solid course ("dry ice") both to serve equally a source of reactant and to absurd the reaction organization to a temperature low enough for the sodium hydrogen carbonate to precipitate:
$$\mathrm{NaCl}(a q)+\mathrm{NH}_{3}(a q)+\mathrm{H}_{2} \mathrm{O}(l)+\mathrm{CO}_{2}(s) \rightarrow$$
$$\qquad \mathrm{NH}_{4} \mathrm{Cl}(a q)+\mathrm{NaHCO}_{3}(south)$$
Because they are relatively cheap, sodium chloride and water are typically nowadays in excess. What is the expected yield of NaHCO, 30.0 $\mathrm{thou}$ of one performs such a synthesis using 10.0 $\mathrm{g}$ of ammonia and xv.0 $\mathrm{g}$ of dry ice, with an excess of NaCl and h2o?

Rachel Five.

Numerade Educator

Trouble 48

A favorite demonstration amongst chemistry teachers, performed to show that the backdrop of a compound differ from those of its constituent elements, involves fe filings and powdered sulfur. If the teacher takes samples of iron and sulfur and simply mixes them together, the two elements can be separated from each other with a magnet (fe is attracted to a magnet, sulfur is not). If the teacher and so combines and heats the mixture of iron and sulfur, a reaction takes place and the elements combine to class iron(Ii) sulfide (which is not attracted by a magnet).
$$\mathrm{Fe}(southward)+\mathrm{Due south}(s) \rightarrow \operatorname{FeS}(southward)$$
Suppose that v.25 g of iron filings is combined with 12.seven of sulfur. What is the theoretical yield of iron(I) sulfide?

Rachel Five.

Numerade Educator

Problem 49

When the sugar glucose, $\mathrm{C}_{six} \mathrm{H}_{12} \mathrm{O}_{six},$ is burned in air, carbon dioxide and water vapor are produced. Write the counterbalanced chemic equation for this process, and calculate the theoretical yield of carbon dioxide when ane.00 $\mathrm{g}$ of glucose is burned completely.

Rachel V.

Numerade Educator

Problem fifty

The traditional method of analyzing the amount of chloride ion present in a sample was to deliquesce the sample in h2o and so slowly add a solution of silverish nitrate. Silver chloride is very insoluble in water, and by calculation a slight excess of silver nitrate, it is possible to finer remove all chloride ion from the sample.
$$\mathrm{Ag}^{+}(a q)+\mathrm{Cl}^{-}(a q) \rightarrow \mathrm{AgCl}(s)$$
Suppose that a 1.054$\cdot \mathrm{g}$ sample is known to comprise ten.iii$\%$ chloride ion by mass. What mass of silver nitrate must be used to completely precipitate the chloride ion from the sample? What mass of silverish chloride will be obtained?

Rachel V.

Numerade Educator

Trouble 51

Consider the balanced equation
$$\mathrm{C}_{3} \mathrm{H}_{8}(g)+5 \mathrm{O}_{ii}(g) \rightarrow three \mathrm{CO}_{2}(one thousand)+iv \mathrm{H}_{ii} \mathrm{O}(chiliad)$$
What mole ratio enables you to summate the number of moles of oxygen needed to react exactly with a given number of moles of $\mathrm{C}_{3} \mathrm{H}_{8}(one thousand) ?$ What mole ratios enable you to calculate how many moles of each product course from a given number of moles of $\mathrm{C}_{3} \mathrm{H}_{viii} ?$

Rachel V.

Numerade Educator

Problem 52

For each of the following counterbalanced reactions, calculate how many moles of each production would be produced by consummate conversion of 0.50 mol of the reactant indicated in boldface. Indicate conspicuously the mole ratio used for the conversion.
a. $ii \mathbf{H}_{2} \mathbf{O}_{2}(l) \rightarrow 2 \mathrm{H}_{2} \mathrm{O}(l)+\mathrm{O}_{two}(g)$
b. $ii \mathrm{KClO}_{3}(s) \rightarrow 2 \mathrm{KCl}(s)+iii \mathrm{O}_{2}(m)$
c. $two \mathbf{A} \mathbf{I}(s)+6 \mathrm{HCl}(a q) \rightarrow$
$\qquad 2 \mathrm{AlCl}_{three}(a q)+3 \mathrm{H}_{ii}(chiliad)$
d. $\mathbf{C}_{three} \mathbf{H}_{8}(g)+5 \mathrm{O}_{two}(g) \rightarrow iii \mathrm{CO}_{two}(g)+4 \mathrm{H}_{two} \mathrm{O}(k)$

Rachel Five.

Numerade Educator

Problem 53

For each of the following balanced equations, signal how many moles of the product could be produced by complete reaction of 1.00 1000 of the reactant indicated in boldface. Indicate clearly the mole ratio used for the conversion.
a. $\mathbf{N H}_{3}(g)+\mathrm{HCl}(thousand) \rightarrow \mathrm{NH}_{4} \mathrm{Cl}(s)$
b. $\mathbf{C a O}(s)+\mathrm{CO}_{two}(thou) \rightarrow \mathrm{CaCO}_{3}(due south)$
c. $4 \mathrm{Na}(s)+\mathrm{O}_{2}(g) \rightarrow ii \mathrm{Na}_{ii} \mathrm{O}(s)$
d. $two \mathrm{P}(s)+3 \mathrm{Cl}_{2}(thousand) \rightarrow 2 \mathrm{PCl}_{three}(l)$

Rachel V.

Numerade Educator

Trouble 54

If sodium peroxide is added to h2o, elemental oxygen gas is generated:
$$\mathrm{Na}_{2} \mathrm{O}_{2}(s)+\mathrm{H}_{2} \mathrm{O}(fifty) \rightarrow \mathrm{NaOH}(a q)+\mathrm{O}_{2}(g)$$
Suppose that iii.25 $\mathrm{g}$ of sodium peroxide is added to a large excess of h2o. What mass of oxygen gas volition exist produced?

Rachel V.

Numerade Educator

Trouble 55

The gaseous hydrocarbon acetylene, $\mathrm{C}_{ii} \mathrm{H}_{2},$ is used in welders' torches considering of the big amount of rut released when acetylene burns with oxygen.
$$2 \mathrm{C}_{2} \mathrm{H}_{two}(g)+5 \mathrm{O}_{ii}(chiliad) \rightarrow four \mathrm{CO}_{2}(one thousand)+2 \mathrm{H}_{2} \mathrm{O}(g)$$
How many grams of oxygen gas are needed for the complete combustion of 150 chiliad of acetylene?

Rachel V.

Numerade Educator

Problem 56

For each of the following unbalanced chemical equations, suppose that 25.0 yard of each reactant is taken. Show by calculation which reactant is limiting. Calculate the theoretical yield in grams of the product in boldface.
a. $\mathrm{C}_{2} \mathrm{H}_{5} \mathrm{OH}(l)+\mathrm{O}_{2}(m) \rightarrow \mathbf{C O}_{ii}(g)+\mathrm{H}_{2} \mathrm{O}(50)$
b. $\mathrm{N}_{two}(g)+\mathrm{O}_{two}(chiliad) \rightarrow \mathbf{N O}(g)$
c. $\mathrm{NaClO}_{ii}(a q)+\mathrm{Cl}_{ii}(g) \rightarrow$
$\qquad \mathrm{ClO}_{2}(one thousand)+\mathbf{N a C l}(a q)$
d. $\mathrm{H}_{2}(g)+\mathrm{Northward}_{2}(g) \rightarrow \mathbf{N H}_{iii}(g)$

Rachel V.

Numerade Educator

Trouble 57

Hydrazine, $\mathrm{Due north}_{2} \mathrm{H}_{four}$ , emits a large quantity of energy when it reacts with oxygen, which has led to hydrazine'due south apply equally a fuel for rockets:
$$\mathrm{N}_{2} \mathrm{H}_{iv}(l)+\mathrm{O}_{2}(g) \rightarrow \mathrm{N}_{2}(m)+two \mathrm{H}_{2} \mathrm{O}(g)$$
How many moles of each of the gaseous products are produced when 20.0 g of pure hydrazine is ignited in the presence of 20.0 g of pure oxygen? How many grams of each production are produced?

Rachel V.

Numerade Educator

Trouble 58

Before going to lab, a student read in her lab manual that the percent yield for a difficult reaction to be studied was likely to be but xl.% of the theoretical yield. The student'southward prelab stoichiometric calculations predict that the theoretical yield should exist 12.5 m. What is the student's actual yield likely to exist?

Rachel V.

Numerade Educator

Trouble 59

When a certain element whose formula is $\mathrm{10}_{4}$ combines with HCl, the results are $\mathrm{XCl}_{iii}$ and hydrogen gas. Write a counterbalanced equation for the reaction. When 24.0 $\mathrm{g}$ of hydrogen gas results from such a reaction, it is noted that 248 $\mathrm{thou}$ of $\mathrm{10}_{4}$ are consumed. Identify element $\mathrm{10}$ .

Rachel V.

Numerade Educator

Problem 60

When a $v.00-\mathrm{yard}$ sample of element $\mathrm{X}$ reacts completely with a $15.0-\mathrm{grand}$ sample of element $\mathrm{Y},$ chemical compound $\mathrm{XY}$ is formed. When a $3.00-\mathrm{chiliad}$ sample of element X reacts with an 18.0 -g sample of chemical element $Z$ , compound $\mathrm{XZ}_{3}$ is formed. The molar mass of $\mathrm{Y}$ is sixty.0 $\mathrm{k} / \mathrm{mol}$ . Discover the molar masses of $\mathrm{Ten}$ and $\mathrm{Z}$ .

Rachel V.

Numerade Educator

Problem 61

Phosphoric acrid, $\mathrm{H}_{3} \mathrm{PO}_{4},$ can be synthesized from phosphorus, oxygen, and water co-ordinate to the following reactions:
$$\mathrm{P}_{4}(s)+\mathrm{O}_{2}(g) \rightarrow \mathrm{P}_{4} \mathrm{O}_{10}(southward)$$
$$\mathrm{P}_{4} \mathrm{O}_{ten}(s)+\mathrm{H}_{two} \mathrm{O}(l) \rightarrow \mathrm{H}_{3} \mathrm{PO}_{4}(50)$$
If y'all commencement with 20.0 g of phosphorus, 30.0 yard of oxygen gas, and 15.0 g of water, what is the maximum mass of phosphoric acid that tin exist formed?

Rachel V.

Numerade Educator

Problem 62

Which of the following reaction mixtures would produce the greatest corporeality of production, assuming all went to completion? Each involves the reaction symbolized past the equation:
$$\mathrm{Due north}_{2}+3 \mathrm{H}_{2} \rightarrow ii \mathrm{NH}_{3}$$
a. 1 mole of $\mathrm{North}_{ii}$ and 3 moles of $\mathrm{H}_{2}$
b. 2 moles of $\mathrm{Due north}_{2}$ and three moles of $\mathrm{H}_{2}$
c. 3 moles of $\mathrm{N}_{ii}$ and 3 moles of $\mathrm{H}_{2}$
d. Each would produce the same amount of product.

Rachel V.

Numerade Educator

Problem 63

Which of the following statements is always true concerning a reaction represented by the following counterbalanced chemical equation?
$$2 \mathrm{C}_{2} \mathrm{H}_{6}(grand)+7 \mathrm{O}_{2}(g) \rightarrow 6 \mathrm{H}_{2} \mathrm{O}(50)+4 \mathrm{CO}_{2}(g)$$
a. If we react equal masses of $\mathrm{C}_{2} \mathrm{H}_{6}$ and O $_{ii}$ , there is no limiting reactant.
b. If we react an equal number of moles of $\mathrm{C}_{two} \mathrm{H}_{6}$ and $\mathrm{O}_{two},$ in that location is no limiting reactant.
c. If we react a greater mass of $\mathrm{C}_{2} \mathrm{H}_{half-dozen}$ than of $\mathrm{O}_{ii},$ then $\mathrm{O}_{2}$ must be limiting.
d. If nosotros react a greater mass of $\mathrm{O}_{ii}$ than of $\mathrm{C}_{ii} \mathrm{H}_{half-dozen},$ then $\mathrm{C}_{two} \mathrm{H}_{6}$ must be limiting.

Rachel V.

Numerade Educator

Problem 64

Determine the limiting reactant and mass of left-over reactant when a 50.0 g sample of $\mathrm{CaO}$ is reacted with 50.0 $\mathrm{g}$ of carbon according to the balanced equation
$$2 \mathrm{CaO}(due south)+5 \mathrm{C}(s) \rightarrow 2 \mathrm{CaC}_{2}(s)+\mathrm{CO}_{2}(1000)$$

Rachel 5.

Numerade Educator

Problem 65

A sample of 13.97 $\mathrm{g} \mathrm{KClO}_{three}$ is decomposed according to the unbalanced equation
$$\mathrm{KClO}_{3}(s) \rightarrow \mathrm{KCl}(due south)+\mathrm{O}_{ii}(chiliad)$$
After the reaction 6.23 $\mathrm{thou} \mathrm{KCl}$ is collected. What is the percent yield of your experiment?

Rachel V.

Numerade Educator

Problem 66

True or simulated? The limiting reactant is always the reactant that is present in the smallest amount (with respect to mass). Provide mathematical support for your answer using the chemical equation $\mathrm{N}_{two}+3 \mathrm{H}_{2} \rightarrow two \mathrm{NH}_{3}$ .

Rachel V.

Numerade Educator

Problem 67

You have vii airtight containers each with equal masses of chlorine gas $\left(\mathrm{Cl}_{2}\right) .$ You add 10.0 $\mathrm{one thousand}$ of sodium to the first sample, 20.0 $\mathrm{g}$ of sodium to the second sample, and so on (ading 70.0 $\mathrm{g}$ of sodium to the seventh sample). Sodium and chlorine react to form sodium chloride co-ordinate to the equation
$$2 \mathrm{Na}(south)+\mathrm{Cl}_{ii}(g) \rightarrow two \mathrm{NaCl}(s)$$
Afterwards each reaction is complete, you collect and measure the amount of sodium chloride formed. A graph of your results is shown below.
IMAGE IS NOT AVAILABLE TO Re-create
Answer the following questions:
a. Explain the shape of the graph.
b. Summate the mass of sodium is used.
c. Calculate the mass of $\mathrm{Cl}_{2}$ in each container.
d. Summate the mass of NaCl formed when 50.0 g of sodium is used.
due east. Identify the leftover reactant and determine its mass for parts b and d higher up.

Rachel V.

Numerade Educator