Goal
Demonstrate your understanding of the information presented in Chapter 1.What to Do
Carefully read the instructions before answering each set of questions. You may consult the solubility table on the last page of the test and a periodic table.
True/False
On the line provided, indicate whether each statement is true (T) or false (F). If the sentence is false, rewrite it to make it true.
___ 1. The brown spots that form on a banana as it sits on your kitchen counter are evidence of a chemical reaction.
___ 2. All ionic substances that contain acetate ions are soluble in water.
___ 3. The formation of new chemical bonds is always an endothermic process.
___ 4. A closed system does not allow any exchange of matter between the system and its surroundings.
___ 5. In a formation reaction, two or more elements react to form a single compound.
Matching
Match each description in column A with the correct term in column B. Write the letter for the term on the line beside the description.
A
___ 6. An insoluble solid formed a chemical reaction in solution.
___ 7. A chemical reaction in which energy is absorbed. ___ 8. The total mass of the reacting substances must equal the
total mass of the resulting substances.
___ 9. An organic compound that contains only the elements carbon and hydrogen.
___ 10. The amount of a substance that contains as many elementary entities as exactly 12 g of carbon-12.
B
(a) hydrocarbon (b) exothermic reaction (c) open system
(d) endothermic reaction (e) combustion reaction (f) mole
(g) molar mass
(h) neutralization reaction (i) Avogadro’s number (j) precipitate
(k) law of conservation of mass (l) law of conservation of energy
Fill in the Blanks
Complete each sentence with the correct term
11. A(n) ______________________________________ is another term for a chemical change (a change in which one or more substances change into other substances).
12. A(n) ______________________________________ reaction is any chemical reaction in which there is a net absorption of energy.
13. A(n) ______________________________________ is a system that is able to exchange substances with its surroundings
14. A(n) ______________________________________ reaction is any chemical reaction in which a single compound breaks down into two or more simpler substances.
15. The ______________________________________ of any substance is the mass of exactly one mole of the substance.
Multiple Choice
17. The reaction that produces nitrogen dioxide from its elements is endothermic. The correct chemical equation for this reaction is
(a) N2(g) + O2(g) NO2(g) + thermal energy
(b) N2(g) + O2(g) + thermal energy NO2(g)
(c) N2(g) + 2O2 (g) 2NO2(g) + thermal energy
(d) N2(g) + 2O2(g)+ thermal energy 2NO2(g)
Use the following information to answer the next three questions:
A. 2CH4 + 3O2 2CO2 + 2H2O + thermal energy
B. Zn + H2SO4 H2 + ZnSO4 + thermal energy
C. Co(NO3)2 + 2KOH Co(OH)2 + 2KNO3 + thermal energy
D. H2 + Cl2 2HCl + thermal energy
18. A precipitate is most likely formed in reaction (a) A
(b) B (c) C (d) D
19. Which statement is correct?
(a) Reaction A is a double replacement reaction. (b) Reaction B is a simple decomposition reaction. (c) Reaction C is a single replacement reaction. (d) Reaction D is a formation reaction.
20. The reaction that does not produce a gas is reaction (a) A
(b) B (c) C (d) D
21. In which reaction does a precipitate form? (a) AgNO3(aq) + NH4NO3(aq) →
(b) Fe(NO3)2(aq) + Na2S(aq) →
(c) NH4Cl(aq) + NaOH(aq) →
22. Ripening fruit produces ethane gas, C2H6(g). When ethane gas is burned in air, it forms carbon dioxide gas and
water vapour. What coefficients are necessary to balance the following equation for the combustion of ethane gas?
___C2H6(g) + ___O2(g) ___CO2(g) + ___H2O(g)
(a) 1, 6, 2, 2 (b) 3, 5, 4, 3 (c) 2, 7, 4, 6 (d) 1, 2, 2, 3
23. In the production of phosphate-based fertilizers, calcium phosphate is reacted with sulfuric acid. The solid product of this reaction is commonly called gypsum. The IUPAC name of this solid is
(a) calcium sulfate
(b) calcium hydrogenphosphate (c) hydrogensulfate
(d) phosphorus metal
24. Dinitrogen monoxide gas (commonly known as “laughing gas”) is sometimes administered to patients to help them relax while a dentist works on their teeth. The molar mass of this compound is
(a) 46.01 g/mol (b) 28.02 g/mol (c) 32.00 g/mol (d) 44.02 g/mol
25. Carbon tetrachloride (a toxic chemical) was used for a time as a dry-cleaning chemical. What is the mass of 1.20 mol of carbon tetrachloride?
(a) 56.9 g (b) 96.0 g (c) 128 g (d) 171 g
Short Answer
Answer each question in the space provided.
26. Complete the following table by writing the formula and predicting the solubility of each compound.
Name Formula High or low solubility?
27. List four (4) indications that a chemical change has occurred.
28. What determines whether a reaction will be exothermic or endothermic? Explain briefly.
Long Answer
Answer each question in the space provided. Be sure to use complete sentences.
29. Suppose that you were given 66.0 g of ammonium sulfate, (NH4)2SO4. Answer the questions that follow. Show
your work.
(a) What is the molar mass of ammonium sulfate?
(b) What amount (in mol) of ammonium sulfate were you given?
(c) How many formula units of ammonium sulfate does the amount (in mol) correspond to?
(d) What amount (in mol) of hydrogen atoms are in the sample of ammonium sulfate?
Solubility Table
Ions NH4+ NO3–
ClO3–
ClO4–
CH3COO– Cl–
Br–
I–
SO42– S2– OH– CO32–
PO43–
SO32–
High solubility
all all most most most group 1
group 2 NH4+
group 1 NH4+
Sr2+
Ba2+
T1+
group 1 NH4+
Low
solubility none none Ag
+
Hg+
Ag+
Pb2+
Cu+
Hg+
T1+
Ag+
Pb2+
Ca2+
Ba2+
Sr2+
Ra2+
6. (b) 7. (c) 8. (b) 9. (c) 10. (b) 11. (d) 12. (d) 13. (b) 14. (d) 15. (a) 16. (d) 17. (d) 18. (b) 19. (b) 20. (c) 21. (a) 22. (d) 23. (d) 24. (a) 25. (a) 26. 3214 27. 2850 28. 1479 29. 1332
30. (a) 2C4H10(g) + 13O2(g) 8CO2(g) + 10H2O(g)
(b) The reaction is exothermic. Although a match is required to initiate the combustion, a large amount of energy is released in the form of heat and light.
(c) The reaction is complete combustion. Because the combustion takes place in pure oxygen, there is sufficient oxygen for complete combustion to occur. In an incomplete combustion reaction, carbon monoxide and carbon would be produced.
(d) There are equal numbers of carbon atoms, hydrogen atoms, and oxygen atoms on each side of the equation. Atoms are not transformed, destroyed, or created. Therefore, the mass of the reactants is equal to the mass of the products. (e) The molar mass of butane is 49.42 g/mol.
