Question

Caffeine has the molecular formula, C8H10N4O2. What is the percent composition of caffeine?

Select one:

a)33.33% C, 41.67% H, 16.67% N, and 8.33% O

b)49.48% C, 5.19% H, 28.85% N, and 16.48% O

c)25% C, 25% H, 25% N, 25% N, and 25% O

d)27.92% C, 2.34% H, 32.56% N, and 37.19% O

Answer 1

b) 49.48% C, 5.19% H, 28.85% N, and 16.48% O

Step-by-step explanation:

According to this question, caffeine has a molecular formula of C8H10N4O2. In order to find the percentage composition of each element in this compound, we must first find the molar mass of the compound:

C8H10N4O2

Where; C = 12, H = 1, N = 14, O = 16

12(8) + 1(10) + 14(4) + 16(2)

96 + 10 + 56 + 32

194g/mol

Next, we find the percent composition of each element as follows by dividing mass of each element by molar mass of the compound and multiplying by 100

C = 96/194 × 100 = 49.48%

H = 10/194 × 100 = 5.15%

N = 56/194 × 100 = 28.86%

O = 32/194 × 100 = 16.49%