The temporary hardness of a water sample is due to compound X. Boiling this sample converts X to compound Y. X and Y, respectively, are:

Options

A. `Mg(HCO_(3))_(2)` and `MgCO_(3)`
B. `Ca(HCO_(3))_(2)` and CaO
C. `Mg(HCO_(3))_(2)` and `Mg(OH)_(2)`
D. `Ca(HCO_(3))_(2)` and `Ca(OH)_(2)`

Answer

C

Explanation

`2Mg(HCO_(3))_(2) overset(Delta) to 2MgCO_(3) + H_(2)O + CO_(2)`
`CO_(3)^(-2)+ H_(2)O to HCO_(3)^(-) + OH^(-)`
`Mg^(+2) + 2OH^(-) to Mg(OH)_(2)`
`X: Mg(HCO_(3))_(2)`
`Y: Mg(OH)_(2)`