Ru school of chinese thought

CHEM. 107 – GENERAL CHEMISTRY I

WINTER 2019

Name: Date:

Show all calculations to get full credit where applicable.

1) If the atomic mass of A is 99, B is 93, and C is 22, what is the molar mass of A3(BC3)4?

2) Calculate the percent of chlorine by mass in PCl3.

3) If the atomic mass of A is 20 and B is 78, what is the molar mass of A3B5?

4) A student wants to make 100 mL of 0.30 M HCl. How many milliliters of 6.0 M HCl is needed to make this solution?

5) How many grams of NaOH will react completely with 296 mL of 0.250 M HCl?

NaOH (aq) + HCl (aq) → NaCl (aq) + H2O (l)

6) In the reaction of N2 and H2 to produce NH3, how many moles of N2 will produce 2.3 moles NH3?

7) If 150.0 mL of HCl solution are required to react completely with 0.35 mol of solid NaOH, what is the molarity of the HCl solution?

HCl (aq) + NaOH (s)  NaCl (aq) + H2O

8) What is the mass percent carbon in C2H6O?

9) In the reaction of aluminum metal and oxygen to make aluminum oxide, how many grams of oxygen gas will react with 1.2 moles aluminum metal?

10) How many moles of N are there in 2.6 moles of HNO3?

11) Calculate the mass, in grams, of a sample containing 1.85 × 1034 molecules of water.

12) In the reaction of N2 and H2 to produce NH3, how many grams of H2 will react with 0.70 moles N2?

13) What mass of nitrogen, in grams, is present in 148 g ammonium sulfate, (NH4)2SO4?

14) Which of the following cannot be an empirical formula?

A) C2H2 B) CH2 C) CH3 D) C2H E) C2H3

15) When the following equation is balanced with lowest ratio whole number coefficients, the coefficient of CO2 is

C4H10 (g) + O2 (g) → CO2 (g) + H2O (1)

16) How many moles of CO2 (g) are produced when 2.9 grams O2 (g) are consumed?

C4H6 (g) + O2 (g) → CO2 (g) + H2O (g) (not balanced)

17) What is the percent yield of the following reaction if 15 g H2O are obtained from the combustion of

18 g C2H6?

2 C2H6 (g) + 7 O2 (g) → 4 CO2 (g) + 6 H2O (g)

18) What is the molarity of a solution in which 6.4 g HCl is dissolved in enough water to make 2.4 L solution?

19) How many milliliters of 1.5 M NaOH will react completely with 448 mL of 0.600 M HCl?

NaOH (aq) + HCl (aq) → NaCl (aq) + H2O (l)

20) When the following equation is balanced, what is the mole ratio of H2O to Be3N2?

Be3N2 + H2O (l) → Be(OH)2 + NH3 (g)

21) How many moles of ammonia are formed for every mole of hydrogen gas that is used in the following reaction?

3 H2 + N2 → 2 NH3

22) A reaction which produces crude iron from iron ore is shown below:

Fe2O3 (s) + 3 CO (g) → 2 Fe (s) + 3 CO2 ( g)

How many moles of iron could be produced from the reaction of 10 mol Fe2O3 and 25 mol of CO?

23) Aluminum and oxygen react according to the following equation:

4 Al (s) + 3 O2 (g) → 2 Al2O3 (s)

In a certain experiment, 4.6 g Al was reacted with excess oxygen and 6.8 g of product was obtained. What was the percent yield of the reaction?

24) Aluminum and oxygen react according to the following equation:

4 Al (s) + 3 O2 (g) → 2 Al2O3 (s)

In a certain experiment, 4.6 g Al was reacted with excess oxygen. If the product was obtained in 64% yield, how many grams were obtained?

25) Calculate the formula mass of ammonium nitrate, a substance used both as a fertilizer and as an explosive.

26) Calculate the mass, in grams, of 0.333 mol CO2.

27) When 0.125 mol butane, C4H10, is burned with excess oxygen, ideally how many moles of carbon dioxide are formed?

2 C4H10 (g) + 13 O2 (g) → 8 CO2 (g) + 10 H2O (l)

28) What mass of KOH, in grams, is required to prepare 125 mL of 2.35 M KOH?

29) What would be the molarity of a solution obtained by diluting 125 mL of 6.00 M HCl to 500. mL?

30) How many moles of oxygen atoms are there in 2.25 moles of BaSO4

31) If 4.0 moles of hydrogen gas and 1.1 moles of nitrogen gas are brought together to react according to the following equation, which will be the limiting reactant?

3 H2 + N2 → 2 NH3

32) How many iron ions (Fe3+) are present in 43.6 g FeCl3?

33) Calculate the number of moles of CO present in a 125 g sample of the gas.