Uracil is base present in RNA with the following structure. % of N in uracil is ______. Given: Molar mass $\mathrm{N}=14 \mathrm{~g} \mathrm{~mol}^{-1} ; \mathrm{O}=16 \mathrm{~g} \mathrm{~mol}^{-1} ; \mathrm{C}= 12 \mathrm{~g} \mathrm{~mol}^{-1} ; \mathrm{H}=1 \mathrm{~g} \mathrm{~mol}^{-1}$;

JEE Main · 2023 · 24 Jan 2023 · Shift 1 · Some Basic Concepts of Chemistry

Uracil is base present in RNA with the following structure. % of N in uracil is ______.

Given:
Molar mass

N = 14 g mol^{- 1}; O = 16 g mol^{- 1}; C = 12 g mol^{- 1}; H = 1 g mol^{- 1}

;

Answer: 25

Uracil has the molecular formula

C_{4} H_{4} N_{2} O_{2}

, so its molar mass is

4 (12) + 4 (1) + 2 (14) + 2 (16) = 112 g mo l^{- 1}

. The two nitrogen atoms contribute

2 \times 14 = 28 g

, so the mass percentage of nitrogen is

\frac{28}{112} \times 100 = 25

JEE Main · 2023 · 24 Jan 2023 · Shift 1 · Integer answer