Question

If 0.98 moles of BaCl2 are dissolved in enough water to make a 1.2-liter solution, what is the resulting molarity?

A. 0.55 M BaCl2
B. 0.82 M BaCl2
C. 1.2 M BaCl2
D. 0.45 M BaCl2

Answer 1

The answer is B. 0.82 M BaCl2

How to generate the answer:

Let:

n = amount of substance
V = volume of solution

Equation for n:

n (BaCl2) = 0.98 mol. (unit of mole)

Equation for V:

V (solution) = 1.2L

Required:

c(BaCl2) =?

Equation for the whole problem:

c(BaCl2) = n (BaCl2) / V (solution)

c(BaCl2) = 0.98 mol / 1.2L

c(BaCl2) = 0.82 mol/L

= 0.82 M

Thus,

the resulting molarity is 0.82 M BaCl2

Answer 2

Correct Answer: Option B i.e. 0.82 M

Reason:
Given: number of moles of BaCl2 = 0.98, Volume of solution = 1.2 l

Molarity of solution =
`\frac{\text{number of moles}}{\text{volume of solution (l)}}`
=
`(0.98)/(1.21)`
= 0.82 M

Thus, molarity of the solution is 0.82 M