Chapter 2 Practice Questions PDF

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Practice problems on stoichiometry, molar mass....

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Practice Exam 2 Multiple choice questions: 1. Which of the following is an empirical formula? a. N2F2 b. CH4 c. C2H6 d. C2H3O2H

2. The molecular formula of a compound is always _________ empirical formula. a. Different b. The same as c. A fraction of d. An integral multiple of

3. Which of the following has highest percent composition by mass of carbon? a. C2H6 b. C2H6OH c. CH4 d. C3H6O2

4. A precipitate is ________________ a. An ion that is not involved in a chemical reaction b. An insoluble solid deposited from a solution c. A substance that is converted to another substance to make a stable compound d. A soluble compound

5. How many grams are there of 0.30 mol of CO2? a. 10g b. 11g c. 12g d. 13g

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6. If 5.00g of Al is burned completely in excess oxygen gas, 9.45g of an aluminum oxide is formed. What is the empirical formula of that oxide? a. AlO3 b. Al2O3 c. Al3O2 d. Al3O

7. What is the percent composition of N in the following compound Mg(NO3)2 ? a. 15.89% b. 16.89% c. 17.89% d. 18.89%

8. What is the empirical formula for the following compound HO2CC4H8CO2H? a. C2H3O b. C3H5O2 c. C4H5O3 d. C5H7O4

9. What is the mass of 6.4 x 1022 molecule of SO2? a. 4.8g b. 5.8g c. 6.8g d. 7.8g

10. What is one visible evidence that a chemical may be occurring? a. Change in color b. No gas formed c. Solutions are forming two layers d. No spectator ion

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11. Which class of reaction would fit into the following category: A compound reactant produces two elements products. a. Combustion b. Combination or synthesis c. Decomposition d. Single-displacement

12. Predict the products if any reaction occurs when Mg(s) and NiCl2 (aq) are mixed. a. MgCl2(aq) and NiCl (aq) b. Ni (s) and Cl2(g) c. Mg(s) and Ni(s) d. MgCl2(aq) and Ni(s)

13. C2H2 (g) reacts with oxygen gas to form CO2 and H2O. What are the coefficients of CO2 and H2O in this reaction? a. 3 CO2 and 1 H2O b. 4 CO2 and 2 H2O c. 5 CO2 and 3 H2O d. 6 CO2 and 4 H2O

14. Which of the following compound is insoluble in water? a. NaCl b. AgCl c. CaCl2 d. KCl

15. Which of the following is insoluble in water? a. Na2SO4 b. BaSO4 c. Rb2SO4 d. K2SO4

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Free Response Questions: 1. Write complete, balanced equations for each of the following reactions:

a) Decomposition of CaCO3 to form solid calcium oxide and carbon dioxide gas

b) Copper and silver nitrate react to produce copper (II) nitrate and silver

c) Lead (II) nitrate reacts with sodium bromide to produce lead (II) bromide and sodium nitrate

2. Balance the following chemical equation: a. ___FeBr3

b. ___Fe

+

+

___O2

c. ___C7H16

d. ___NH3

___H2SO4

+

+

___O2

f. ___Mg(OH)2

g. ___SiCl4

h. ___HClO4

+

+

+

 ___CO2

 ___NO

___Pb(NO3)4

___HCl

___H2O

+

+

___HBr

 ___Fe2O3

___O2

e. ___ (NH4)3PO4

 ___Fe2(SO4)3

___P4O10

+

+

___H2O

___H2O

 ___Pb3(PO4)4

 ___MgCl2

 ___SiO2

+

 ___H3PO4

+

+

___HO

___HCl

+

___Cl2O7

___NH4NO3

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3. Write the net ionic equation for the following: a. AgNO3(aq)

+

KCl(aq)

Æ

AgCl(s)

+

KNO3(aq)

Molecular Equation:

Total Ionic Equation:

Net ionic equation:

b. Iron (II) oxide and hydrochloric acid to produce iron(II) chloride and water. Molecular Equation:

Total Ionic Equation:

Net ionic equation:

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4. Using the activity series table, predict whether the following single – replacement can occur. If it does occur, write the chemical formulas of the products along with the physical states and balance the equation. If not, write NR.

a. Cu +

FeSO4 Æ _______________________________________________________________

b. Solid zinc

c. Zn +

+

aqueous silver acetate Æ ________________________________________

H2SO4 Æ _________________________________________________________________

d. Solid Magnesium +

e. Al +

Aqueous hydrochloric acid Æ __________________________________

Pb(NO3)2 Æ _______________________________________________________________

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5. Predict whether the following double-replacement can occur. If it does occur, write the chemical formulas of the products along with the physical states. Balance the equation. If not, write NR.

a. BaCl2(aq) +

Na2SO4(aq)

b. Potassium bromide (aq) +

c. Na2CO3(aq) +

d. Sulfuric acid(aq)

Æ __________________________________________________________

Calcium chloride (aq)

Æ ______________________________________

HCl(aq) Æ _____________________________________________________________

+ Potassium hydroxide(aq) Æ __________________________________________

6. How many carbon atoms are there in 10.2g of CO2?

7. How many grams of HNO3 acid that contains 2.02 x 1023 atoms of nitrogen?

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8. How many molecules of carbon dioxide in 1.58g of carbon dioxide?

9. How many grams of Fe element that consists of 4.58x1023 atoms of Fe?

10. An unknown compound containing C, H and O was determined to have the following percent compositions: 40.00%C, 6.72% H and the rest is oxygen. a. What is the empirical formula of this compound? b. Given the molar mass of this compound is 180.0 g/mol. What is its molecular formula?...