If the density of lake water is 1.25 g `mL^(-1)` and it contains 92 g of `Na^(+)` ions per kg of water, calculate the molality of `Na^(+)` ions in the lake.

Answer

`m=4`

Explanation

`W_(2)=92g,Mw_(2)=23g`
`W_(1)=1kg=1000g`
`m=(92xx1000)/(23xx10000)=4`