Q&A - Ask Doubts and Get Answers
Q

what is the solution for this?

An aqueous solution of NaCl is marked 10% (w/w). If the density of the solution is 1.071 gmL-1, what is the molality?

A.

1.85 M

B.

1.90 M

C.

1.95 M

D.

2.0 M

Answers (1)
9 Views

Molality -

Molality (m) = (number of moles of solute)/(mass of solvent in kg)

 

- wherein

It is defined as the number of moles of solute present in 1 kg of solvent. It is denoted by m.

 

 Weight of salute = 10g

Moles of salute   =10/58.5          (Weight/Molecular weight)

Weight of solvent = 90 g

Molality=(10*1000)/(58.5*90)=1.90m

 

Exams
Articles
Questions