Question

Which solution has the highest concentration of NaCl?

A. 175 g NaCl in 1.0 L

B. 58.5 g NaCl in 1.5 L

C. 29.3 g NaCl in 0.5 L

D. 2.5 mol NaCl in 2.0 L

E. 5.0 mol NaCl in 3.0 L

Answer 1

A)

Molar mass of NaCl = 1*MM(Na) + 1*MM(Cl)

= 1*22.99 + 1*35.45

= 58.44 g/mol

mass of NaCl = 175 g

we have below equation to be used:

number of mol of NaCl,

n = mass of NaCl/molar mass of NaCl

=(175.0 g)/(58.44 g/mol)

= 2.995 mol

volume , V = 1.0 L

we have below equation to be used:

Molarity,

M = number of mol / volume in L

= 2.995/1

= 2.995 M

Answer: 3.00 M

B)

mass of NaCl = 58.5 g

we have below equation to be used:

number of mol of NaCl,

n = mass of NaCl/molar mass of NaCl

=(58.5 g)/(58.44 g/mol)

= 1.001 mol

volume , V = 1.5 L

we have below equation to be used:

Molarity,

M = number of mol / volume in L

= 1.001/1.5

= 0.6674 M

Answer: 0.667 M

C)

mass of NaCl = 29.3 g

we have below equation to be used:

number of mol of NaCl,

n = mass of NaCl/molar mass of NaCl

=(29.3 g)/(58.44 g/mol)

= 0.5014 mol

volume , V = 0.5 L

we have below equation to be used:

Molarity,

M = number of mol / volume in L

= 0.5014/0.5

= 1.003 M

Answer: 1.00 M

D)

volume , V = 2.0 L

we have below equation to be used:

Molarity,

M = number of mol / volume in L

= 2.5/2

= 1.25 M

Answer: 1.25 M

E)

volume , V = 3.0 L

we have below equation to be used:

Molarity,

M = number of mol / volume in L

= 5/3

= 1.667 M

Answer: 1.67 M