Unit 7: Chemical Reactions

What kind of change occurs when paper is shredded into small pieces?

• Chemical Change

• Phase Change

• Physical Change

• Atomic Change

Which of the following is a chemical change?

• Dissolving sugar in water

• Melting ice

• Tearing a paper

• Baking a cake

Which formula needs a roman numeral in its name?

• AlF₃

• CaCO₃

• Sn(NO₂)₂

• NaCl

What is always true in a balanced chemical equation?

• There are more products than reactants

• The mass of products is less than the mass of reactants

• The number of atoms for each element is equal on both sides

• The number of molecules is always the same

Which of the following equations is correctly balanced?

• H₂ + O₂ → H₂O

• 2H₂ + O₂ → 2H₂O

Which statement is true about covalent compounds?

• They use roman numerals

• They require prefixes in naming

• They only form with metals

• They always form precipitates

What is the formula for disulfur decafluoride?

• S10F2

• S3F9

• S2F10

• S2F8

Which of the following shows the net ionic equation for CaCO₃ precipitation?

• Na⁺ + Cl⁻ → NaCl

• Ca²⁺ + CO₃²⁻ → CaCO₃ (s)

• Na₂CO₃ + CaCl₂ → CaCO₃ + 2NaCl

• 2Na⁺ + CO₃²⁻ → Na₂CO₃

In a redox reaction, oxidation is defined as:

• Gaining electrons

• Losing electrons

• Gaining protons

• No change in electrons

Which is a redox reaction?

• HCl + NaOH → H₂O + NaCl

• 2AlPO₄ + 3Mg → 2Al + Mg₃(PO₄)₂

• NaCl + AgNO₃ → NaNO₃ + AgCl

• BaCl₂ + Na₂SO₄ → BaSO₄ + NaCl