Question

*multiple choice*

What is the molarity of a 45.3g sample of KNO3 (101g) dissolved in enough water to make a 0.225L solution?

a) 0.45
b) 2
c) option 3
d) none of the above

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

Step-by-step 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 =
`(number of moles)/(volume of the solution)`

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

number of moles =
`(mass)/(atomic mass of 1 mole)`

number of moles =
`(45.3)/(101)`

0.44 moles of KNO3

Putting the values in the equation of molarity:

molarity =
`(0.44)/(0.225)`

molarity = 1.95

It can be taken as 2.

The molarity of the potassium nitrate solution is 2.