NEW
Font size
WorksheetsCHEMISTRY_X_C.R.E
Total questions: 10
Worksheet time: 6mins
1.Magnesium ribbon is rubbed before burning because it has a coating of
(a) basic magnesium carbonate
(b) basic magnesium oxide
(c) basic magnesium sulphide
(d) basic magnesium chloride
2. In a chemical reaction between sulphuric acid and barium chloride solution the white precipitates formed are of:
a.hydrochloric acid
b.bariumsulphate
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.physical process
d.reversible process
4. Which of the following are exothermic processes?
(i) Reaction of water with quick lime
(ii) Dilution of an acid
(iii) Evaporation of water
(iv) Sublimation of camphor (crystals)
(a) (i) and (ii)
(b) (ii) and (iii)
(c) (i) and (iv)
(d) (ii) and (iv)
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
6. 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
a. (i) and (ii)
b. (i) and (iii)
c. (i), (iii) and (iv)
d. (iii) and (iv)
7.Rusting of iron involves a chemical reaction which is a combination of:
a. Reduction as well as combination reactions
b. Oxidation as well as combination reactions
c. Reduction as well as displacement reactions
d. Oxidation as well as displacement reactions
You are given the above chemical reaction:
This reaction represents:
a. Combination reaction as well as double displacement reaction.
b. Redox reaction as well as displacement reaction
c. Double displacement reaction as well as redox reaction
d. Decomposition reaction as well as displacement reaction
9.When ferrous sulphate is heated strongly it undergoes decomposition to form ferric oxide as a main product accompanied by a change in colour from:
a. Blue to green.
b. Green to blue.
c. Green to brown.
d. Green to yellow.
10. MnO2 + 4HCl → 2 + 2H2O + Cl2
Identify the substance oxidized in the above . equation.
(a) MnCl2
(b) HCl
(c) H2O
(d) MnO2
