Question

Moles of Na2S0, to be dissolved in 12 mole water to lower its vapour pressure by 10 mm Hg
at a temperature at which vapour pressure of pure water is 50 mm is:
(a) 1.5 mole
(b) 2 mole
(c) 1 mole
(d) 3 mole​

Answer 1

Answer:

Correct answer is ( C ) .

but it is Na2So4 not Na2So