Chemistry Past Questions and Answers

\(50cm^{3}\) of hydrogen are sparked with \(20cm^{3}\) of oxygen at \(100°C\) and \(1atm\) . The total volume of the residual gases in

A 50 cm3
B 10 cm3
C 40 cm3
D 30 cm3
E 70 cm3

Question 122:

How many grams of HBr would exactly be required to react with 2 g of propyne? (C =12, H=1, Br = 80)

A 4. 1 g
B 6. 1 g
C 8. 1g
D 16.2g

Question 123:

When ammonium, potassium and calcium carbonates are each separately heated

A None of them will decompose
B Each of them will decompose to give carbondioxide and the respective oxide
C Ammonium carbonate and potassium carbonate will not decompose
D Only ammonium carbonate and the respective oxide
E Ammonium carbonate will decompose to give carbondioxide, water and ammonia

Question 124:

If chlorine gas is bubbled into water and then this yellowish-green coloured solution is exposed to bright sunlight for a while

A The solution will give out chlorine gas and hydrogen chloried gas
B The solution will produce chlorine gas and oxygen
C The solution will give out solution will producing hypochloric acid
D The solution is decomposed giving out oxygen, hydrogen and chlorine
E The solution will give out oxygen gas leaving behind aqueous hydrochloric acid

Question 125:

12 g of solid protassium chlorate (KCIO) were added to 40 g of water and heated to dissolve all the solid. As the solution cools, crystals of potassium chlorate at 66 oC. The solubility of potassium chlorate at 66 oC is therefore

A 66
B 33
C 10
D 20
E 30