Exams › JEE Main › Chemistry

A sodium sulfate solution contains 92 g of Na+ per kilogram of water. Find the molality of Na+ ions (mol/kg).

1. 16
2. 8
3. 4
4. 12

Correct answer: 4

Solution

92 g of Na+ is 92/23 = 4 mol, in 1 kg water, so molality = 4 mol/kg.

Related JEE Main Chemistry questions

• A sulphuric acid solution has a concentration of 3.60 M and contains 29% H2SO4 by mass. If the molar mass of H2SO4 is 98 g mol⁻¹, what is the density of the solution in g mL⁻¹?
• Which one of the following substances is absent in clear hard water?
• Fractional distillation is chosen in a situation where
• Car radiators use an aqueous ethylene glycol solution as antifreeze. How much ethylene glycol should be mixed with 5 kg of water so that the freezing point is lowered to -0.3 °C? (K_f = 1.86 K kg mol⁻¹)
• A solution contains a non-volatile solute of molecular mass M₂. Which expression can be used to determine the molecular mass of the solute using osmotic pressure?
• At 298 K, the Henry’s law constant for oxygen is 1.4 × 10⁻³ mol L⁻¹ atm⁻¹. If oxygen is at a partial pressure of 0.5 atm, what mass of oxygen will dissolve in 100 mL of water at 298 K?

⚔️ Practice JEE Main Chemistry free + battle 1v1 →