JEE MAIN - Chemistry (2019 - 9th January Morning Slot - No. 13)

A solution of sodium sulphate contains 92 g of Na+ ions per kilogram of water. The molality of Na+ ions in that solution in mol kg$$-$$1 is :
12
4
8
16

Explanation

Molality of Na+ = $${{Moles\,\,of\,\,N{a^ + }} \over {mass\,\,of\,\,{H_2}O\,\,in\,\,kg}}$$

Moles of Na+ = $${{92} \over {23}}$$ = 4

Mass of H2O = 1 kg

$$ \therefore $$   Molality = $${4 \over 1}$$ = 4

Comments (0)

Advertisement