THERE ARE 2 QUEST. Q1. a metal carbonate X on reacting with an acid gives a gas wihch passed through solution Y gives the carbonate black. on the other hand, a gas G that is obtained at the anode during electrolysis of brine is passed on dry Y, it gives a compound Z, used for disinfecting water. identify X,Y.G and Z. Q2. a dry pellet of common base B, when kept in open absorbs moisture and turns sticky. the compound is also a product of chloralkali process. identify B. what type of reaction occurs when Bis treated with acidic oxide? please give a balanced equation for one such solution.

Asked by  | 18th Aug, 2012, 01:31: AM

Expert Answer:

The metal carbonate x is CaCO3. When it reacts with an acid, produces a salt , water and CO2 which when passed through a solution y that is Ca(OH)2 [ slaked lime ] gives back the carbonate.

CaCO3 + HCl -> CaCl + H2O +C

x + acid -> CaCl + H2O + CO2

CO Ca(OH) 2 -> CaCO3 + H 2 O


CaCO3 is limestone

Chlorine is generated on anode when electrolysis of brine is carried out. 2Cl- - 2e- ? Cl2

When it is passed over dry CaCO3, it forms Z, which is CaOCl2.

Ans 2 

Sodium hydroxide (NaOH) is a commonly used base and it absorbs moisture from the atmosphere and becomes sticky. 

The acidic oxides react with base to give salt and water. Lets take an acidic oxide- Carbon dioxide. The reaction between NaOH and CO2 can be given as

2 NaOH + CO2 ---------> Na2CO3 + H2O .

Answered by  | 18th Aug, 2012, 09:21: AM

Queries asked on Sunday & after 7pm from Monday to Saturday will be answered after 12pm the next working day.