Question

A solution is made containing 8.4 g

of potassium nitrate per 125 g of
water.
What is the weight/weight % or
percent by mass of the solute?

Answer 1

The percent by mass : 6.3%

Further explanation

The concentration of a substance can be expressed in several quantities such as moles, percent (%) weight/volume,), molarity, molality, parts per million (ppm) or mole fraction. The concentration shows the amount of solute in a unit of the amount of solvent.

mass of potassium nitrate = 8.4 g⇒solute

• mass of solution = mass of solute+mass of solvent(water)

mass of potassium nitrate + mass of water = 8.4 g + 125 g =133.4 g

Percent by mass of the solute :

`\tt =(mass~solute)/(mass~solution)* 100\%\\\\=(8.4)/(133.4)* 100\%\\\\=6.3\%`