Question

The molarity of NACL having density 1 g per ML and 1.52 ppm of sodium is 6.6 x 10^-x find the value of x

Answer 1

The value of X is -5

• Given, Molarity of NaCl solution = 6.6* 10^ -X
• Density of the solution = 1g/ml
• Na+ concentration = 1.52 ppm
• Now, we know ppm means number of parts of solute in 1 million part of solution.
• So, on conversion, 1.52 ppm means
• 1.52g per 10^6 gm of solution.
• 1.52 mg per 1 kg of solution.
• Also density = weight / volume ,

So 1 L of solution = 1 * 1000 gm , i.e 1 L of solution = 1 Kg of solution

• That is, concentration of solute = 1.52 * 10^-3 g/L
• Now, we know Molarity = Concentration / Molar mass
• Molarity of NaCl  = 1.52 * 10 ^-3 /58.44 = 2.6 * 10 ^-5
• Therefore, value of X is -5.

Answer 2

The value of x is equal to 5.

• Molarity of a subsatnce is defined as the number of moles of the solute present per litre of the solution.
• 1 ppm of a substance means that 1 mg of the substance is present in 1 kg of the solution.
• Since, ppm of sodium is 1.52 and density of the solution is 1 g/mL , 1.52 mg of sodium is present in one litre of the solution.
• Hence, moles of sodium presentin one liter of the solution is equal to 6.6*10^-5 moles (1.52*10^-3/23).
• Since every mole of NaCl contains one mole of sodium, the number of moles of NaCl present per litre of the solution is equal to 6.6*10^-5.
• Therefore, the molarity of NaCl is equal to 6.6*10^-5 M.