Question

32 g of NaOH is dissolved in enough water to make a 325 mL solution. Calculate the molarity of solution

Answer 1

Solution:

No. of mole of solute(NaOH)= given mass/molar mass
= 32/40
= 0.8 moles

Molarity= no. of moles of solute/volume of solution in L
= 0.8*1000/325
= 2.46 mol/L

I hope its helpful

Answer 2

Answer:

The molarity of the solution ( $NaOH$ + $H_{2}O$ ) calculated is $2.461M$.

Explanation:

Given data,

The given mass of $NaOH$ dissolved in water, m = $32g$

The volume of the solution ( $NaOH$ + $H_{2}O$ ), V = $325ml$

Convert ml into L

• $1ml$ = $0.001L$
• $325ml$ = $0.325L$

The given solution's ( $NaOH$ + $H_{2}O$ )molarity =?

As we know,

• Molarity = $\frac{Number of moles ( solute ) }{Volume ( solution )}$     -------equation (1)

For this, we have to find out the number of moles of solute ( $NaOH$ ):

As we know, the molar mass of $NaOH$ = $40g/mol$

• Number of moles of $NaOH$ = $\frac{Given mass}{Molar mass}$ = $\frac{32}{40}$ = $0.8mol$

Now, after putting the calculated value of the number of moles of $NaOH$ and the given volume of solution in equation (1), we get:

• Molarity = $\frac{Number of moles ( solute ) }{Volume ( solution )}$
• Molarity = $\frac{0.8}{0.325}$
• Molarity = $2.461M$

Hence, the given solution's ( $NaOH$ + $H_{2}O$ )molarity = $2.461M$.