12 Exercise 2 SolutionsUsing Molarities And

1.2 Exercise 2 - solutions

Using molarities and concentrations

1. Calculate the number of moles of H2SO4 in 50 cm3 of a 0.50 moldm-3 solution.

2. Calculate the number of moles of FeSO4 in 25 cm3 of a 0.2 moldm-3 solution.

3. Calculate the mass of KMnO4 in 25 cm3 of a 0.02 moldm-3 solution.

4. Calculate the mass of Pb(NO3)2 in 30 cm3 of a 0.1 moldm-3 solution.

5. What is the molarity of 1.06g of H2SO4 in 250 cm3 of solution?

6. What is the molarity of 15.0 g of CuSO4.5H2O in 250 cm3 of solution?

7. What volume of a 0.833 moldm-3 solution of H2O2 will be required to make 250 cm3 of a 0.100 moldm-3 solution?

8. What volume of a 0.50 moldm-3 solution of HCl will be required to make 100 cm3 of a 0.050M solution?

9. How many moles of NaCl are there in 25 cm3 of a 50 gdm-3 solution?

Reacting masses and volumes

1. 25 cm3 of a solution of 0.1 moldm-3 NaOH reacts with 50 cm3 of a solution of hydrochloric acid. What is the molarity of the acid?

2. 25.0 cm3 of a 0.10 moldm-3 solution of sodium hydroxide was titrated against a solution of hydrochloric acid of unknown concentration. 27.3 cm3 of the acid was required. What was the concentration of the acid?

3. 10 cm3 of a solution of NaCl react with 15 cm3 of a 0.02 moldm-3 solution of AgNO3. What is the concentration of the NaCl solution in gdm-3?

4. 25 cm3 of a 0.1 moldm-3 solution of an acid HxA reacts with 75 cm3 of a 0.1 moldm-3 solution of NaOH. What is the value of x?
Equation: HxA + xNaOH  + NaxA + xH2O

5. A solution of hydrochloric acid of volume 25.0 cm3 was pipetted onto a piece of marble which is calcium carbonate. When all action had ceased, 1.30g of the marble had dissolved. Find the concentration of the acid
Equation: CaCO3 + 2HCl  CaCl2 + CO2 + H2O

6. What volume of 0.1 moldm-3 hydrochloric acid would be required to dissolve 2.3 g of calcium carbonate?
Equation: CaCO3(s) + 2HCl(aq)  CaCl2(aq) + CO2(g) + H2O(l)

7. 2.05 g of the carbonate of an unknown alkali metal (X2CO3) required 8.9 cm3