PRE-MID TERM Class -10th (SCIENCE)

In a chemical reaction between sulphuric acid and barium chloride solution the white precipitates formed are of:

• Hydrochloric acid

• Barium sulphate

• Chlorine

• Sulphur

The respiration process during which glucose undergoes slow combustion by combining with oxygen in the cells of our body to produce energy, is a kind of:

• Exothermic process

• Endothermic process

• Reversible process

• Physical process

A chemical reaction does not involve:

• Formation of new substances having entirely different properties than that of the reactants

• Breaking of old chemical bonds and formation of new chemical bonds

• Rearrangement of the atoms of reactants to form new products

• Changing of the atoms of on element into those of another element to form new products

One of the following processes does not involve a chemical reaction. That is:

• Melting of candle wax when heated

• Burning of candle wax when heated

• Digestion of food in our stomach

• Ripening of banana

It is necessary to balance a chemical equation in order to satisfy the law of:

• Conservation of motion

• Conservation of momentum

• Conservation of energy

• Conservation of mass

All the methods mentioned below can be used to prevent the food from getting rancid except:

i. Storing the food in the air-tight containers

ii. Storing the food in refrigerator

iii. Keeping the food in clean and covered containers

iv. Always touching the food with clean hands

• (i) and (ii)

• (i) and (iii)

• (i), (iii) and (iv)

• (iii) and (iv)

Rusting of iron involves a chemical reaction which is a combination of:

• Reduction as well as combination reactions

• Oxidation as well as combination reactions

• Reduction as well as displacement reactions

• Oxidation as well as displacement reactions

When ferrous sulphate is heated strongly it undergoes decomposition to form ferric oxide as a main product accompanied by a change in colour from:

• Blue to green.

• Green to blue.

• Green to brown.

• Green to yellow.

Which of the following gases is used in the storage of fat and oil containing foods for a long time?

• Carbondioxide gas

• Nitrogen gas

• Oxygen gas

• Neon gas

The neutralization reaction between an acid and a base is a type of:

• Double displacement reaction

• Displacement reaction

• Displacement reaction

• Decomposition reaction