Question

3. "X" is a water insoluble compound of calcium. On strong heating gives a colourless
odourless gas 'Y' and a white residue Z. When Y is passed through lime water a
milkiness forms which disappears on further passage of Y Y is also formed when X
is dropped in dilute hydrochloric acid. Answer the following questions on the basis of
above observations
(2) Give chemical equation and category of reaction of formation of Y on heating
(b) What is milkiness and why does it disappear?
(c) What is Z and what is its name?
(d) What happens when X is dropped in dilute hydrochloric acid ? Give equation.​

Answer 1

CaCO3 + dil. H2SO4 → CaSO4 + H2O + CO2

(Water insoluble)

(A)                          (B)

Ca(OH)2 + CO2 → CaCO3 + H2O

(Lime water)           (A)

                           Milky

A - CaCO3 (Lime water)

B - CO2(g)