Question Papers

Class – X
Subject – Science
Acids, Bases and Salts

Why should sour substances not kept in brass and copper vessels?1
Why do HCl and HNO3 show acidic behaviour in water while ethanol and glucose do not yet they contain hydrogen in them? 1
How is concentration of OH- ions affected when excess of base is dissolved in water? 1
A baker found that the cake prepared by him is hard and small in size. Which ingredient has he forgotten to add? Give reason. 2
Name the compound which is used to remove hardness of water. 1
What will happen if heating is not controlled in preparing of plaster of Paris? Give equation. 2
A certain compound is alkaline is nature. On exposure to air, it turns into a white opaque powder. Identify the compound and mention its two uses. 3
A white substance having smell of chlorine is used in paper and textile industries. Identify the substance and write the equation of its preparation. 3
What is water of crystallization? Which two features of crystals generally depend on it? 2
What is the concentration of H3O+ and OH- ions in pure water at 25°C? How do these vary when acid is added? 2
Classify the following into acidic, basic and neutral salts. 2
(NH4) 2CO3 b) BaSO4 c) NaNO3 d) K2SO4