Question

what is the molarity of a solution containing 1 g kno₃ in 202 ml?
add your answer
question 19
the mass percent of a solution containing 25 g in 125 g of water is 16.7%.
please give the answer to one decimal.
blank 1 16.7

Explanation:

Step1: Calculate moles of KNO₃

The molar mass of KNO₃ (K: 39.1 g/mol, N: 14.0 g/mol, O: 16.0 g/mol) is $39.1+14.0 + 3\times16.0=101.1$ g/mol. The number of moles $n$ of KNO₃ with mass $m = 1$ g is $n=\frac{m}{M}=\frac{1\ g}{101.1\ g/mol}\approx0.0099$ mol.

Step2: Convert volume to liters

The volume $V$ of the solution is $202$ mL. Convert it to liters: $V = 202\ mL\times\frac{1\ L}{1000\ mL}=0.202$ L.

Step3: Calculate molarity

The molarity $M$ is given by the formula $M=\frac{n}{V}$. Substitute $n = 0.0099$ mol and $V=0.202$ L into the formula: $M=\frac{0.0099\ mol}{0.202\ L}\approx0.049$ M.

Answer:

0.049 M