Chemical Formulas (Reading Passage)

What is the chemical formula for water?

• H₂O

• CO₂

• NaCl

• O₂

Explain the significance of the numbers in a chemical formula.

How many oxygen atoms are present in a molecule of carbon dioxide? CO₂

• One

• Two

• Three

• Four

Describe how chemical formulas help scientists in their work.

• Chemical formulas are only used in cooking recipes.
• Chemical formulas can predict the weather accurately.
• Chemical formulas are irrelevant to scientific research.
• Chemical formulas help scientists communicate the composition of substances, understand reactions, and predict properties.

What elements make up the compound NaCl?

• Sodium and Chlorine

• Sodium and Oxygen

• Chlorine and Oxygen

• Hydrogen and Oxygen

How does the chemical formula for glucose differ from that of methane?

• Glucose (C6H12O6) has fewer carbon atoms than methane (CH4).
• Methane (CH4) contains nitrogen, while glucose (C6H12O6) does not.
• Glucose (C6H12O6) contains oxygen, while methane (CH4) does not.
• Both glucose and methane have the same number of hydrogen atoms.

Identify the compound with the chemical formula Al₂(SO₄)₃ and describe its common use.

• Aluminum oxide is used in battery production.
• Aluminum chloride is used in food preservation.
• Aluminum hydroxide is used as a fertilizer.
• Aluminum sulfate (Al₂(SO₄)₃) is commonly used in water purification.