Question 1
1. An acid volume 11.30 cm The equation of the reaction is: HCl(aq) + NaOH(aq) ) → NaCl((aq) + H2O(l) (a) From the information provided, calculate the: (i) concentration of the base in mol dm-3 (ii) value of Y (iii) mass of NaCl formed during the reaction. (b) (i) State the indicator that can best be used for the titration.
(ii) State the colour of the indicator mentioned in 1 (b)(i) at the end point.
[H =1.0; O = 16.0; Na = 23.0; Cl = 35.5]
[18 marks]
Observation
This was a popular question among the candidates as their performance in it was above average.
In part (a), majority of the candidates were able to calculate the concentration of the base in moldm-3. Also, the mass of NaCl formed during the reaction was calculated.
In part (b), majority of the candidates stated correctly the indicator that can best be used for the titration.
The expected answers include:
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