STOICHIOMETRY QUIZ Part III

1. Determine the mass (g) of solute required to form 275 mL of a 0.5 M KClO4 solution. (Ar K = 39, O = 16, Cl = 35.5).
a. 19.6
b. 12.2
c. 8.6
d. 4.2
e. 1.97
2. For reasons of taste, the maximum chloride ion content of domestic water supplies has been set at 0.025 g/L. What is the maximum content of chloride ion in moles per liter? (Ar Cl = 35.5).
a. 9.0 x 10-2
b. 7.1 x 10-4
c. 7.1 x 10-2
d. 9.0 x 10-3
e. 5.0 x 10-4
3. If some water are added to 10 cm3 of hydrochoric acid 2M and forms 100 cm3 of solution, the new molarity of the acid is ….
a. 0,1 mol dm-3
b. 0,2 mol dm-3
c. 0,3 mol dm-3
d. 0,4 mol dm-3
e. 0,5 mol dm-3
4. Fluoxymesterone, C20H29FO3, is an anabolic steroid. A solution is prepared by dissolving 10.0 mg of the steroid in 500.0 mL of water. A 1.00 mL portion of this solution is diluted to a final volume of 1.00 L. What is the resulting molarity? (Ar C = 12, O = 16, F = 19, H = 1).
a. 1.19 x 10-7
b. 5.94 x 10-11
c. 5.94 x 10-8
d. 2.38 x 10-11
e. 1.19 x 19-10
5. A solution is prepared by dissolving 516.5 mg of oxalic acid (C2H2O4) to make 100.0 mL of solution. A 10.00 mL portion is then diluted to 250.0 mL. What is the molarity of the final solution? (Ar C = 12, H = 1, O = 16).
a. 5.7 x 10-2
b. 2.3
c. 2.3 x 10-3
d. 5.7 x 10-2
e. 5.7
6. How many moles of lead chromate, PbCrO4, the pigment "chrome yellow", often used by artists, can be produced by addition of excess sodium chromate, Na2CrO4, to 25 mL of a 0.493 M solution of lead(II) nitrate, Pb(NO3)2? (Ar Pb = 207, Cr = 52, O = 16, Na = 23).
Pb(NO3)2+Na2CrO4 --> 2 NaNO3+PbCrO4
a. 0.018
b. 0.024
c. 0.006
d. 0.012
e. 0.015
7. How many moles of calcium carbonate, CaCO3, are required to react with the sulfuric acid in 375.4 mL of a 0.9734 M solution of H2SO4? (Ar Ca = 40, C = 12, O = 16).
CaCO3(s)+H2SO4(aq) --> CaSO4(s)+H2O+CO2
a. 0.1829
b. 0.1256
c. 0.7132
d. 0.3654
e. 0.8238
8. What mass of the active metal magnesium is required to react exactly with the hydrochloric acid in a 125.0 mL sample of a 0.2110 M solution of HCl? (Ar Mg = 24).
Mg(s) + 2 HCl(aq) --> MgCl2(aq) + H2(g)
a. 0.27
b. 0.16
c. 0.21
d. 0.32
e. 0.29
9. What volume, in mL, of 0.265 M HBr will react completely with 0.155 g of zinc? (Ar Zn = 65.4, Br = 80, H = 1).
Zn + 2 HBr --> ZnBr2 + H2
a. 15
b. 8.9
c. 7.3
d. 18
e. 4.5
10. What volume of 0.0916 M BaCl2 will react completely with 0.475 g of Na2SO4? (Ar Ba = 137, S = 32, Cl = 35.5, Na = 23, O = 16).
BaCl2 + Na2SO4 --> BaSO4 + 2 NaCl
a. 28.8
b. 31.2
c. 33.4
d. 36.5
e. 41.6
11. Calcium carbonate solid is added to a solution of hydrochloric acid. The molarity of acid is 2,0 M and the mass of calcium carbonate (Mr = 100) is 10 grams. The volume of HCl(aq) which needed in this reaction is ….
a. 25 mL
b. 100 mL
c. 50 mL
d. 150 mL
e. 75 mL