Question

Quinine, an antimalarial drug, is 8.63% nitrogen. There are two nitrogen atoms per molecule. What is the molecular weight of quinine? (Atomic weight: N = 14.01).

Answer 1

324.18 g/mol

Step-by-step explanation:

Let the molecular mass of the antimalarial drug, Quinine is x g/mol

According to question,

Nitrogen present in the drug is 8.63% of x

So, mass of nitrogen =
`\frac {8.63}{100}* x`

Also, according to the question,

2 atoms are present in 1 molecule of the drug.

Mass of nitrogen = 14.01 amu = 14.01 g/mol (grams for 1 mole)

So, mass of nitrogen = 14.01×2 = 28.02

These 2 must be equal so,

`\frac {8.63}{100}* x=28.02`

solving for x, we get:

x = 324.18 g/mol