Question

if 4g of NAOH is dissolved in 36g of H2O calculate mass percent and molarity of NAOH solution prepared. ​​

Answer 1

GIVEN:

mass of solute = 4g

mass of solvent = 36g

TO FIND:

• mass percent
• Molarity

FORMULA:

$\% \: mass \: = \frac{mass \: of \: solute}{mass \: of \: solvent}$

$molarity = \frac{moles \: o f\: solute}{vol \: of \: soln}$

SOLUTION:

(1)

mass percent = 4/36 ×100 =1/9=11%

(2)

moles of solute

= mass /molar mass

=4/40

=0.1 moles

moles of H2 0

=36/18

=2

total moles = 2+0.1 =2.1

moles = V soln /22.4

V soln = 2.1×22.4

V soln =47.04 L

Molarity

=0.1/47.04

=0.002M