Chemistry 2202 Unit 1 Test 2 ICA Part 1 – Multiple Choice: Complete each item using the answer form on page 4. (1 point per item) 1.

Which statement about the synthesis of sodium chloride is correct? 2 Na (s)

A. B. C. D. 2.



Cl2(g)

2 NaCl (s)

Two atoms of sodium will react with two molecules of chlorine. Two formula units of sodium produce two atoms of sodium chloride. Two grams of sodium will react with one gram of chlorine. Two moles of sodium produce two moles of sodium chloride.

According to the information given, what mass of chlorine is required to react? 2 Na (s)



Cl2 (g)

12.5 g

A. B. C D. 3.





2 NaCl (s)

?

31.8 g

9.65 g 19.3 g 25.6 g 38.6 g

Most modern gas barbeques use the heat produced by the combustion of propane. 1 C3H8(g)



5 O2(g)



3 CO2(g)



4 H2O (g)

Which mole ratio should be used to determine the amount of carbon dioxide produced by the combustion of 3.6 mol O2 ? A.

B.

4.

1 mol C3H8

C.

4 mol H2O 3 mol CO2

D.

4 mol H2O

3 mol CO2 5 mol O2

5 mol O2 3 mol CO2

In the metallurgy of galena, PbS, the first step involves the roasting of the ore. 2 PbS (s)



3 O2(g)



2 PbO (s)



2 SO2(g)

How many moles of oxygen should be consumed if 0.500 mol PbS are roasted? A. 0.333 mol B. 0.500 mol C. 0.750 mol D. 1.50 mol

5.

Gravimetric stoichiometry refers to quantitative analysis involving which quantity? A. B. C. D.

6.

formula units mass molecules volume

How many moles of sulfur should react with 75.4 g of potassium? 2 K (s)

A. B. C. D. 7.

S (s)



S (s)



K2S (s)

27.6 g 55.1 g 110 g 221 g

What amount of ammonia, NH3, will be produced by the reaction of 0.230 mol of hydrogen, H2, at STP? N2(g)

A. B. C. D.



3 H2(g)



2 NH3(g)

0.153 mol 3.43 mol 7.73 mol 10.3 mol

How many moles of ammonia, NH3, will be produced by the complete reaction of 16.4 L of hydrogen at STP? N2(g)

A. B. C. D. 10.

K2S (s)

What mass of potassium sulfide will be produced if 0.500 mol of sulfur reacts completely? A. B. C. D.

9.



0.964 mol 1.18 mol 3.85 mol 5.73 mol

2 K (s)

8.





3 H2(g)



2 NH3(g)

0.488 mol 0.732 mol 1.10 mol 146 mol

Which term means ‘the chemical species that is completely consumed in a chemical reaction’ ? A. B. C. D.

excess species gravimetric species limiting species product species

11.

A reaction occurs between copper metal and ions of dissolved silver nitrate. Cu (s)



2 AgNO3 (aq)



Cu(NO3 )2(aq)



2 Ag (s)

When the reaction is complete, the addition of sodium chloride to the reaction vessel causes the formation of another solid, silver chloride. What species is correctly identified? A. B. C. D. 12.

copper metal – excess species copper nitrate – limiting species silver chloride – limiting species silver nitrate – excess species

A mixture of 6.00 mol of lead and 4.00 mol of sulfur is heated: Pb (s)



2 S (s)



PbS2(s)

What is in excess? A. 1.00 mol S B. 2.00 mol Pb C. 4.00 mol Pb D. Neither Pb nor S is in excess. 13. Sally and Harry complete a laboratory activity that involves the production and collection of a precipitate by filtration. They discover that the amount collected is less than what was expected. They identify and list the most likely errors in the activity. Which is a systematic error? A. B. C. D. 14.

Susan and Bart react solutions of lead(II) nitrate and potassium iodide. Their prelab calculations indicate that 5.63 g of lead(II) iodide would be formed. After filtration they weighed out 6.11 g of lead(II) iodide. How would you refer to the 6.11 g mass? A. B. C. D.

15.

calculating the expected mass incorrectly decanting too much solution into the funnel filtering the solution before the reaction was finished using a reactant that had been contaminated at some time.

the actual yield the expected yield the percent yield the theoretical yield

Calculations indicate that 3.76 g of copper should be formed in a single replacement reaction. The recovered mass of copper is 3.20 g. What is the percent yield for the reaction? A. B. C. D.

14.9 % 85.1 % 100 % 118 %

Chemistry 2202 - Unit 1 Test 2 Part 1: For each item, circle the letter corresponding to your choice. 1.

A

B

C

D

6.

A

B

C

D

11.

A

B

C

D

2.

A

B

C

D

7.

A

B

C

D

12.

A

B

C

D

3.

A

B

C

D

8.

A

B

C

D

13.

A

B

C

D

4.

A

B

C

D

9.

A

B

C

D

14.

A

B

C

D

5

A

B

C

D

10. A

B

C

D

15.

A

B

C

D

Part 2: Write your responses in the spaces provided. Show all workings and be neat! 16.

Verify that the Law of Conservation of Mass is upheld in the reaction: 2 Fe (s)

17.



3 Cl2(g)



(3)

2 FeCl3(s)

Nitrogen gas is produced in an automobile air bag by the decomposition of sodium azide, NaN3. 2 NaN3(s)



3 N2(g)



2 Na (s)

Calculate the volume of N2 produced at STP when 124 g NaN3 decomposes.

(4)

18.

Solid iron reacts in a single replacement reaction with copper(II) chloride solution. Fe (s)

(a)

19.



CuCl2(aq)



FeCl2(aq)



Cu (s)

In the laboratory, students react 4.25 g Fe with excess copper(II) chloride and collect 4.00 g of Cu product. i)

Calculate the theoretical yield of copper.

(3)

ii)

Calculate the percent yield.

(1)

The first step in the production of nitric acid is to react ammonia with oxygen to form nitrogen monoxide and water vapor. 4 NH3 (g)



5 O2(g)



4 NO (g)



6 H2O (g)

Identify the excess and limiting species if 0.128 mol NH3 is mixed with 0.150 mol O2. Justify your answer.

(2)