Titration and calculations test questions - WJEC

1

For the results of a titration to be concordant (in close agreement), what volume must the titres be within?

2

Which piece of apparatus is used to add small measured volumes of one reactant to the other reactant in a titration?

3

Why is it important to place the conical flask on a white tile when doing a titration?

4

Which part of the meniscus should be used when reading the volume of liquid in the burette?

5

What is the concentration in mol/dm3 of the solution that is formed when 50.50 g of potassium nitrate (KNO3) is dissolved in 250 cm3 of water? [Higher tier only]

6

A student found that 25.6 cm3 of 0.3 mol/dm3 HCl were needed to neutralise a certain volume of 0.1 mol/dm3 sodium carbonate solution. What is the volume of Na2CO3(aq)? [Higher tier only]

Na2CO3 + 2HCl → 2NaCl + H2O + CO2

7

12.5 cm3 of aqueous HNO3 is neutralised by 25 cm3 of 0.02 mol/dm3 barium hydroxide. What is the concentration of the nitric acid? [Higher tier only]

Ba(OH)2 + 2HNO3 → Ba(NO3)2 + 2H2O

8

Ethanoic acid CH3COOH and NaOH react in a 1:1 ratio. 30 cm3 of CH3COOH was found to react with 20 cm3 of 1.5 mol/dm3 NaOH. What mass of ethanoic acid would be present in 1 dm3 of the above solution if Mr (ethanoic acid) = 60? [Higher tier only]

9

In an acid-alkali titration, which piece of apparatus is used to measure exactly 25.0 cm3 of alkali into the conical flask?

10

In a titration, the first titre value was 23.50 cm3. The next few titre values were 22.40, 22.80 and 22.90. Which two values should be used to calculate the average titre?