Question

Calculate the concentration in % of a solution containing 150g MgBr2 in 500 mL of solution.

Question 96 options:

	0.3%
	30%
	0.003%
	3.33%

Answer 1

Solution: Option 'B' 30%

Because, we know percentage means parts per 100.

ie. Percentage of of MgBr2 means weight /mass of MgBr2 per 100 mL solution

In the question, it is given that

Total volume =500mL

Total amount of MgBr2 dissolved in 500mL = 150g

Therefore,

Percentage of MgBr2 in 500mL = (150/500) x 100

= 30%

• Option A is wrong because 0.3% means 1.5 g MgBr2 in 500mL
• Option C is wrong because 0.003% means 0.015 g MgBr2 in 500mL
• Option D is wrong because 3.33% means 16.65 g MgBr2 in 500mL