Question

Class 10th Subject: Science
Chapter:1 Chemical Reactions and Equations
1.Before burning in air, the magnesium ribbon is cleaned by rubbing with a sand paper to:
a. Make the ribbon surface shinier
b. Remove the layer water from the ribbon surface
c. Remove the layer of magnesium carbonate from the ribbon surface
d. Remove the moisture from the ribbon surface

2.In a chemical reaction between sulphuric acid and barium chloride solution the white
precipitate formed are of:
a. Hydrochloric acid
b. Barium sulphate
c. Chlorine
d. Sulphur

3.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:
a. Exothermic process
b. Endothermic process
c. Reversible process
d. Physical process

4.A chemical reaction does not involve:
a. Formation of new substances having entirely different properties than that of the react ants
b. Breaking of old chemical bonds and formation of new chemical bonds
c. Rearrangement of the atoms of react ants to form new products
d. Changing of the atoms of on element into those of another element to form new products

5. One of the following processes does not involve a chemical reaction. That is
a Melting of candle wax when heated
b. Burning of candle wax when heated
c. Digestion of food in our stomach
d. Ripening of banana



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Answer 1

Answer:

1-c

2-b

3-a

4-d

5-a

Explanation:

respiration is an exothermic process in which energy is released....

during melting of candle wax there is no change in its chemical property...