Density of gold is `19.30 g//cm^(3)` at `20^(0)C`. Computer the density of gold at `90^(0)C` by adding steam to it. `(alpha = 14.2 xx 10^(-6 //0) C)`

Explanation

`(rho_(2))/(rho_(1)) = (V_(1))/(V_(2)) = V_(1)/(V_(1)(1 + 3alphaDeltaT)) = (1 + 3alphaDelta)^(-1)`
or `(rho_(2))/(rho_(1)) = (1 - 3alphaDeltaT)` or
`rho_(2) = rho_(1)(1 - 3alphaDeltaT)`
`= (19.30)[1 - 3(14.2 xx 10^(-6)(70)] = 19.24g // cm^(3)`