Answer
a. Mass percent composition (C): 74.87%
b. Mass percent composition (C): 79.88%
c. Mass percent composition (C): 92.24%
d. Mass percent composition (C): 37.23%
Work Step by Step
a.
1. Calculate the molar mass of: $CH_4$
Molar Mass ($CH_4$):
12.01* 1 + 1.008* 4 = 16.04g/mol
2. Calculate the total mass of $C$ in one mole of this compound:
Total Mass ($C$): $ 1 \times 12.01 g = 12.01 g$
3. Find the mass percent composition:
$\frac{Total-mass (C)}{Molar-Mass} \times 100\% = \frac{ 12.01}{ 16.04} \times 100\% = 74.87\%$
b.
1. Calculate the molar mass of: $C_2H_6$
Molar Mass ($C_2H_6$):
12.01* 2 + 1.008* 6 = 30.07g/mol
2. Calculate the total mass of $C$ in one mole of this compound:
Total Mass ($C$): $ 2 \times 12.01g = 24.02g$
3. Find the mass percent composition:
$\frac{Total-mass (C)}{Molar-Mass} \times 100\% = \frac{ 24.02}{ 30.07} \times 100\% = 79.88\%$
c.
1. Calculate the molar mass of: $C_2H_2$
Molar Mass ($C_2H_2$):
12.01* 2 + 1.008* 2 = 26.04g/mol
2. Calculate the total mass of $C$ in one mole of this compound:
Total Mass ($C$): $ 2 \times 12.01 g= 24.02g$
3. Find the mass percent composition:
$\frac{Total-mass (C)}{Molar-Mass} \times 100\% = \frac{ 24.02}{ 26.04} \times 100\% = 92.24\%$
d.
1. Calculate the molar mass of: $C_2H_5Cl$
Molar Mass ($C_2H_5Cl$):
12.01* 2 + 1.008* 5 + 35.45* 1 = 64.51g/mol
2. Calculate the total mass of $C$ in one mole of this compound:
Total Mass ($C$): $ 2 \times 12.01g = 24.02g$
3. Find the mass percent composition:
$\frac{Total-mass (C)}{Molar-Mass} \times 100\% = \frac{ 24.02}{ 64.51} \times 100\% = 37.23\%$
