Question

i) What chemical change would you observe when:

(a) Mercuric oxide is heated.

(b) Dilute HCl is added to zinc metal.

(c) Water is added to quicklime.​

Answer 1

Answer:

Mercury(II) oxide, a red solid, decomposes when heated to produce mercury and oxygen gas. Mercury(II) oxide is a red solid. When it is heated, it decomposes into mercury metal and oxygen gas. A reaction is also considered to be a decomposition reaction even when one or more of the products are still compounds.

b)Zinc metal has silver-gray appearance. When dilute HCl is added to the metal, the zinc chloride so formed (which is white in colour) will dissolve in the aqueous medium and so the solution obtained will be colourless.

c)When Water is added to quick lime, then a lot of heat is released and heavy fizzing occurs because Slaked lime is fromed ( Calcium Hydroxide). CaO + H₂O → Ca(OH)₂ + heat energy.