Exams › JEE Main › Chemistry

Equal masses of NaCl and KCl are each dissolved in equal volumes of solution. How do the molarities of the two solutions compare?

1. Greater for NaCl
2. Equal
3. Greater for KCl
4. Cannot be compared

Correct answer: Greater for NaCl

Solution

For the same mass and volume, the salt with lower molar mass yields more moles and thus higher molarity. NaCl (58.5 g/mol) < KCl (74.5 g/mol), so NaCl solution is more concentrated.

Related JEE Main Chemistry questions

• A 100 mL sample of a urea solution contains 6.02 × 10²⁰ molecules of urea. What is the molarity of the solution? (Take Avogadro constant, N_A = 6.02 × 10²³ mol^−1.)
• When 4.9 g of H2SO4 reacts with NaCl, the products formed are 6 g of sodium hydrogen sulphate and 1.825 g of HCl. What mass of NaCl was decomposed?
• Which of the following has the least mass?
• What amount of magnesium phosphate, Mg3(PO4)2, in moles is needed to provide 0.25 mole of oxygen atoms?
• Haemoglobin has 0.33% iron by mass. If its molecular mass is about 67200 and the atomic mass of iron is 56, how many iron atoms are present in a single haemoglobin molecule?
• For the reaction 2Al(s) + 6HCl(aq) → 2Al³+(aq) + 6Cl^−(aq) + 3H₂(g), which statement is correct?

⚔️ Practice JEE Main Chemistry free + battle 1v1 →