Question

If molarity = moles liter , then how many grams of NaCl are needed to make 1 liter of a 0.1 M solution? A) 0.0584 g NaCl B) 3.246 g NaCl C) 5.844 g NaCl D) 58.44 g NaCl

Answer 1

Answer : Option C) 5.844 g NaCl

Explanation :

To calculate the number of grams of NaCl that would be needed to make 0.1 M of solution we have to calculate;

1. The molecular weight of sodium chloride (NaCl) which is 58.44 g, so one gram molecular weight will be= 1 mole which is 58.44 g.
2. By dissolving 58.44 g of NaCl upto the final volume of 1 litre, one can get 1 M NaCl solution.
3. So, to make 0.1 M NaCl solution we have to dilute the mass of salt to 1000 ml of solution as follows;
4. 0.1 M NaCl solution will require 0.1 x 58.44 g of NaCl = 5.844 g. of NaCl.

Answer 2

The grams of NaCl that needed to make 1L of a 0.1 M solution is

5.845 g (answer C)

calculation

Step 1: find the moles of NaCl

moles = molarity x volume in liters

molarity = 0.1 M =0.1 mol/l

= 1 L x 0.1 Mol/L = 0.1 moles

Step 2: find the mass NaCl

mass = moles x molar mass

From periodic table the molar mass of NaCl = 23 +35.45 =58.45 g/mol

mass= 0.1 moles x 58.45 g/mol =5.845 g appropriate ( answer C)