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

Explanation

Number of moles present in 92 g of `Na^(+)` ions `= (92 g)//(23 g//mol)`
= 4 mol
Therefore, molality of `Na^(+)` ions in the lake
`= (4 mol)/(1 kg)=4 m`