Change Jn PH On Adding Calcium Hydroxidr To A Ficed Volume Of Dilute Hcl

Question 1

What is the best piece of apparatus to measure the volume of hydrochloride acid?

Answer 1

50cm3 measuring cylinder

Question 2

Why is that the best piece of apparatus?

Answer 2

It’s more accurate than using a beaker

Question 3

How do you use universal indicator paper to measure the PH of the solution

Answer 3

The indicator paper changes colour and you match it to the colour chart to show the PH

Question 4

Why is it necessary to stir the mixture when the calcium hydroxide powder is added

Answer 4

To make sure all the powder reacts with an acid

Question 5

What are the main errors in this experiment?

Answer 5

Measuring the mass of the calcium hydroxide accurately

Making sure that all the calcium hydroxide reacts

Question 6

How could you improve the method

Answer 6

Use more precise balance +0.01 or + 0.001
Use a larger volume of acid
Use a narrow range indicator
Use a PH metre

Question 7

How do you know when the hydrochloride acid is exactly neutralised

Answer 7

Use the graph to work out the mass which produced a PH7

Question 8

Why does adding hydroxide ions (OH)- to an acid lead to an increase in PH

Answer 8

The hydroxide ions neutralise the hydrogen ions neutralise the hydrogen (H+) ions. This reduces the concentration of hydrogen ions and reduces PH