Question

the molar mass of Sodium Hydroxide is 40 gram per mole if you dissolve 25 gram of it to make the decimeter cube solution what will be its molarity​

Answer 1

Answer:

1 mol of NaOH has a mass of 40g. So

Moles of NaOH=1.6g of NaOH×

40gNaOH

1molNaOH

​

=0.04 mol NaOH

Litres of solution =500ml solution ×

1000mlSolution

1LSolution

​

=0.5 L Solution

Molarity =

litresofsolution

molesofSolute

​

             =

0.5

0.04

​

 mol/L

             =0.08 mol/L

Explanation:

We know,

Molality =

weight of solvent (kg)

moles

​

Molality =(

molecular weight

weight

​

)×

(volume×density)

1000

​

      [Note: density =1 gm/cm

3

]

Molality =

40

20

​

×

500

1000

​

×1=1 m