PERCENTAGE COMPOSITION

What is percentage composition?

• The mass of a compound divided by its molar mass.

• The ratio of the mass of each element in a compound to the total mass of the compound, expressed as a percentage.

• The percentage of a compound that is composed of oxygen atoms.

• The percentage of a compound that is composed of hydrogen atoms.

How is the percentage composition of a compound calculated?

• By dividing the mass of a compound by its volume.

• By dividing the mass of each element in the compound by the molar mass of the compound and multiplying by 100%.

• By subtracting the mass of each element in the compound from the total mass of the compound.

• By multiplying the mass of each element in the compound by the molar mass of the compound.

What is the percentage composition of water (H₂O)?

(Atomic mass: H=1, O=16)

• 11.11% hydrogen, 88.89% oxygen

• 50% hydrogen, 50% oxygen

• 33.33% hydrogen, 66.67% oxygen

• 20% hydrogen, 80% oxygen

                                 

What is the percentage composition of carbon dioxide (CO₂)?

(Atomic mass: C=12, O=16)

• 27.27% carbon, 72.73% oxygen

• 50% carbon, 50% oxygen

• 40% carbon, 60% oxygen

• 90% carbon, 10% oxygen

What is the percentage composition of methane (CH₄)?

(Atomic mass: C=12, H=1)

• 25% carbon, 75% hydrogen

• 50% carbon, 50% hydrogen

• 75% carbon, 25% hydrogen

• 90% carbon, 10% hydrogen

Which of the following represents the percentage composition of ammonia (NH₃)?

• 16.67% nitrogen, 83.33% hydrogen

• 25% nitrogen, 75% hydrogen

•    82.35% nitrogen, 17.65% hydrogen

• 50% nitrogen, 50% hydrogen

What is the percentage composition of sulfuric acid (H₂SO₄)?

(Atomic mass: H=1, S=32, O=16)

• 2.08% hydrogen, 32.65% sulfur, 65.27% oxygen

• 4.17% hydrogen, 32.65% sulfur, 63.18% oxygen

• 4.17% hydrogen, 65.27% sulfur, 30.56% oxygen

• 4.17% hydrogen, 16.33% sulfur, 79.50% oxygen

What is the percentage composition of sodium chloride (NaCl)?

• 39.34% sodium, 60.66% chlorine

• 50% sodium, 50% chlorine

• 60.66% sodium, 39.34% chlorine

• 66.67% sodium, 33.33% chlorine

A sample of sodium chloride (NaCl) was analyzed and found to contain 58.44% chlorine. What is the mass of chlorine in a 100 gram sample of sodium chloride?

• 58.44 grams

• 41.56 grams

• 29.22 grams

• 16.00 grams

A compound was analyzed and found to contain 12 grams of carbon, 2 grams of hydrogen, and 16 grams of oxygen. What is the percentage composition of hydrogen in the compound?

• 7%

• 5%

• 15%

• 20%