Question

*multiple choice*

Answer 1

1.95  or 2  is the molarity of a 45.3g sample of KNO3 (101g) dissolved in enough water to make a 0.225L solution.

The correct answer is option b

Explanation:

Data given:

mass of KN$O_{3}$ = 45.3 grams

volume = 0.225 litre

molarity =?

atomic mass of KNO3 = 101 grams/mole

molarity is calculated by using the formula:

molarity = $\frac{number of moles}{volume of the solution}$

first the number of moles present in the given mass is calculated as:

number of moles = $\frac{mass}{atomic mass of 1 mole}$

number of moles = $\frac{45.3}{101}$

0.44 moles of KNO3

Putting the values in the equation of molarity:

molarity = $\frac{0.44}{0.225}$

molarity = 1.95

It can be taken as 2.

The molarity of the potassium nitrate solution is 2.