Topic 1 Review. Quantitative Chemistry
1. What is the sum of all coefficients when the following equation is balanced using
the smallest possible whole numbers? __ C2H2 + __O2 → __CO2 + __H2O
2. 1.7g of NaNO3 (Mr = 85) is dissolved in water to prepare 0.20 dm3 of solution.
What is the concentration of the resulting solution in mol dm–3?
3. Which sample has the greatest mass?
A. 1 mol of SO2
B. 2 mol of N2O
C. 2 mol of Ar
D. 4 mol of NH3
4. The relative molecular mass of a gas is 56 and its empirical formula is CH2. What
is the molecular formula of the gas?
5. What mass, in g, of hydrogen is formed when 3 mol of aluminium react with excess
hydrochloric acid according to the following equation?
2Al(s) + 6HCl(aq) → 2AlCl3(aq) + 3H2(g)
6. What is the total number of hydrogen atoms in 1.0 mol of benzamide,
C6H5CONH2?
7. What is the sum of the coefficients for the equation when balanced using the
smallest possible whole numbers?
__N2H4(g) + __O2(g) → __NO2(g) + __H2O(g)
8. Chloroethene, C2H3Cl, reacts with oxygen according to the equation below.
2C2H3Cl(g) + 5O2(g) → 4CO2(g) + 2H2O(g) + 2HCl(g)
What is the amount, in mol, of H2O produced when 10.0 mol of C2H3Cl and 10.0
mol of O2 are mixed together, and the above reaction goes to completion?
9. Which amount of the following compounds contains the least number of ions?
A. 2 mol of NaOH
B. 1 mol of NH4Cl
C. 2 mol of CaCl2
D. 1 mol of Al2O3
10. What is the approximate molar mass, in g mol–1, of MgSO4•7H2O?
11. Which is both an empirical and a molecular formula?
A. C5H12
B. C5H10
C. C4H8
D. C4H10
12. What is the coefficient of Fe3O4 when the following equation is balanced using the
lowest whole numbers?
__ Al(s) + __ Fe3O4(s) → __ Al2O3(s) + __ Fe(s)
13. 6.0 mol of aluminium reacts with oxygen to form aluminium oxide. What is the
amount of oxygen, in mol, needed for complete reaction?
4Al(s) + 3O2(g) → 2Al2O3(s)
14. What is the total number of nitrogen atoms in two mol of NH4NO3?
15. On analysis, a compound with molar mass 60 g mol-3 was found to contain 12 g of
carbon, 2 g of hydrogen and 16 g of oxygen. What is the molecular formula of the
compound?
16. 8.5 g of NH3 are dissolved in H2O to prepare a 500 cm3 solution. Which statements
are correct?
I. NH3 is the solute and H2O is the solution
II. The concentration of the solution is 17 g dm-3
III. [NH3] = 1.0 mol dm-3
A. I and II only
B. I and III only
C. II and III only
D. I, II and III
17. What volume of sulfur trioxide, in cm3, can be prepared using 40 cm3 sulfur
dioxide and 20 cm3 oxygen gas by the following reaction? Assume all volumes are
measured at the same temperature and pressure.
2SO2(g) + O2(g) → 2SO3(g)
18. 4.00 mol of a hydrocarbon with an empirical formula of CH2 has a mass of 280 g.
What is the molecular formula of this compound?
19. Which coefficients would balance this equation?
__ MnO2 + __ HCl → __ MnCl2 + __ Cl2 + __ H2O
20. What does (l), (g), (s), (aq) refer to in a chemical equation?