2 This question is about acids and alkalis.
2-1 Which ion do all acids produce in aqueous solution?
[1 mark]
Tick () one box.
ANSWER
H+
2-2 Calcium hydroxide solution reacts with an acid to form calcium chloride. Complete the word equation for the reaction.
[2 marks]
ANSWER
Calcium chloride + Hydrochloric acid = Calcium Chloride + Water
A student investigates the volume of sodium hydroxide solution that reacts with 25.0 cm3 of dilute sulfuric acid.
Figure 2 shows the apparatus the student uses
Use Figure 2 to answer Questions 02.3 and 02.4
2-3 Name apparatus A.
[1 mark]
ANSWER
Burette
2-4 What is the reading on apparatus A?
[1 mark]
ANSWER
27.6
2-5 The higher the concentration of a sample of dilute sulfuric acid, the greater the volume of sodium hydroxide needed to neutralise the acid.
The student tested two samples of dilute sulfuric acid, P and Q.
Describe how the student could use titrations to find which sample, P or Q, is more concentrated.
[6 marks]
ANSWER
Measure the volume of acid by using pipette,
use a few drops of indicator for adding into acid
add sodium hydroxide solution with the help of burette
Swirl the conical flask and use a white tile so that exact color change point i.e. end point may be identified.
add dropwise near the endpoint & read and record volume from bottom of meniscus of burette,
repeat procedure with the other acid
Results:
Compare the two volumes of sodium hydroxide solution added to find which sample P or Q is more concentrate.
The higher the volume added of Sodium hydroxide for reaching end point, so higher the concentration of dilute sulfuric acid.
