Question

Calculate the mass of sodium bromide dihydrate is required to prepare 250 mL of a 0.00600 M solution

Answer 1

Answer: The mass of sodium bromide dihydrate is 0.208 grams

Explanation:

Molarity of a solution is defined as the number of moles of solute dissolved per liter of the solution.

$Molarity=\frac{n\times 1000}{V_s}$

where,

n = moles of solute

$V_s$ = volume of solution in ml  = 250 ml

moles of $NaBr.2H_2O$ = $\frac{\text {given mass}}{\text {Molar mass}}=\frac{xg}{138.92g/mol}$

Now put all the given values in the formula of molality, we get

$0.00600=\frac{x\times 1000}{138.92\times 250}$

$x=0.208$

Therefore, the mass of sodium bromide dihydrate is 0.208 grams