Previous Year Paper year:2014 : ICSE-X-Chemistry

Home Learn Fast select Course

Change Unit Change Subject Last Menu

ICSE-X-Chemistry

Previous Year Paper year:2014

with Solutions - page 4

#2-a-i
When dilute hydrochloric acid is added to sodium carbonate crystals.
Ans : i. Brisk effervescence with the release of a colourless odourless gas that extinguish a glowing splint and turns lime water milky i.e., CO₂ gas is released.

#2-a-ii
When excess sodium hydroxide is added to calcium nitrate solution.
Ans : ii. A white ppt of Ca(OH)₂ is obtained that remains insoluble in excess of NaOH.

#2-a-iii
At the cathode, when acidified aqueous copper sulphate solution is electrolysed with
copper electrodes.
Ans : iii. The blue colour of aq.CuSO₄ remains unchanged.

#2-a-iv
When calcium hydroxide is heated with ammonium chloride crystals.
Ans : iv. A colourless pungent smelling basic gas i.e., Ammonia is obtained.

#2-a-v [5]
When moist starch iodide paper is introduced into chlorine gas.
Ans : v. Moist starch iodide paper turns blue black.

#2-b
Study the figure given below and answer the questions which follow:

#2-b-i
Identify the gas Y.
Ans : i. Hydrogen chloride gas (HCl).

#2-b-ii
What property of gas Y does this experiment demonstrate?
Ans : ii. Y Gas i.e., HCl gas is highly soluble and acidic in nature.

#2-b-iii [3]
Name another gas which has the same property and can be demonstrated through this
experiment.
Ans : iii. Ammonia gas.

#2-c

#2-c-i
Name the other ion formed when ammonia dissolves in water.
Ans : i. Hydroxyl ion (OH^-) other than Ammonium ion.

#2-c-ii [2]
Give one test which can be used to detect the presence of the ion produced.
Ans : ii. Red litmus turns blue/Methyl orange yellow/Phenolphthalein turns pink.

#3

#3-a
State the conditions required for the following reactions to take place:

#3-a-i
Catalytic hydrogenation of ethyne
Ans : In presence of Catalyst like Ni/Pt/Pd etc.