Unit 1 and 2 Review

Front

Why do groups on the Periodic Table contain elements with similar chemical properties and reactivity?

Back

They have the same number of valence electrons.

Front

What role do valence electrons play in the interaction between two different substances that undergo a chemical change?

Back

The valence electrons are exchanged or shared to form a new substance in a chemical change.

Front

Why do sodium and chlorine easily react with one another?

Back

Sodium only has one valence electron, and chlorine has seven.

Front

The reaction above demonstrates the law of conservation of mass. Which statement is INCORRECT?

• The reaction has the same number and type of atoms in both the reactants and the products
• The products of the reaction are carbon dioxide and water.
• There are 3 atoms of oxygen in the products of this reaction--two in carbon dioxide and one in water.
• There are 9 total atoms in the reactants of this reaction--5 in methane and 4 in oxygen.

Back

There are 3 atoms of oxygen in the products of this reaction--two in carbon dioxide and one in water.

Front

Which statement is BEST supported by the chemical equation shown? 6CO₂ + 12H₂O + light → C₆H₁₂O₆ + 6O₂ + 6H₂O

Back

Six molecules of CO₂ are needed as reactants.

Front

Which chemical equation demonstrates the law of conservation of mass for the combustion of ethane? Options: C₂H₆ + 3O₂ → 2CO₂ + 3H₂O, C₂H₆ + 5O₂ → 2CO₂ + 3H₂O, 2C₂H₆ + 5O₂ → 4CO₂ + 4H₂O, 2C₂H₆ + 7O₂ → 4CO₂ + 6H₂O

Back

2C₂H₆ + 7O₂ → 4CO₂ + 6H₂O

Front

Which chemical equation demonstrates the conservation of matter? Options: 2Sn + 4HNO3 → SnO2 + 4NO2 + 2H2O, I2 + 5Cl2 + 6H2O → 2HIO3 + 10HCl, Cl + 4Na → 4NaCl, 4P + 5HNO3 → 5NO + 3H3PO4

Back

2Sn + 4HNO3 → SnO2 + 4NO2 + 2H2O

Front

Select the point on this pH scale that represents a substance that is slightly basic: pH 6, pH 7, pH 8, pH 9.

Back

pH 8

Front

Select the point (pH number) of TWO substances that have very strong concentrations of H+ ions.

Back

pH 1 and pH 2

Front

Experiment results: Before: Iron filings are brown, small, and magnetic; copper sulfate crystals are blue, brittle, and not magnetic. After: The copper formed was reddish, solid, and not magnetic; iron sulfide solution was colorless and not magnetic. Which statement supports that a chemical reaction took place?

Back

A new substance was formed.