Question

Show the calculation of the molarity of a solution made by dissolving 12.6 grams of NaNO3 to make 200 ml of solution.

Answer 1

Answer: The molarity of a solution made by dissolving 12.6 grams of NaNO3 to make 200 ml of solution is 0.74 M

Explanation:

Molarity is defined as the number of moles of solute dissolved perliter of the solution.

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

where,

n= moles of solute  

$V_s$ = volume of solution in ml = 1000 ml

$moles of solute =\frac{\text {given mass}}{\text {molar mass}}=\frac{12.6g}{85g/mol}=0.148moles$

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

$Molarity=\frac{0.148moles\times 1000}{200ml}=0.74mole/L$

Thus the molarity of a solution made by dissolving 12.6 grams of NaNO3 to make 200 ml of solution is 0.74 M

Answer 2

Answer:

The molarity of the solution is 0.740 M

Explanation:

Step 1: data given

Mass of NaNO3 = 12.6 grams

Molar mass of NaNO3 = 84.99 g/mol

Volume = 200 mL = 0.200 L

Step 2: Calculate moles of NaNO3

Moles NaNO3 = mass NaNO3 / molar mass NaNO3

Moles NaNO3 = 12.6 grams / 84.99 g/mol

Moles NaNO3 = 0.148 moles

Step 3: Calculate molarity

Molarity = moles / volume

Molarity = 0.148 moles / 0.200 L

Molarity = 0.740 M

The molarity of the solution is 0.740 M