Unit 4: Stoichiometry and Chemical Reactions

Which of the following statements is true about water (H2O)?

• Water is a non-polar molecule.

• Water has a linear shape.

• Water can dissolve many different substances.

• Water has a low boiling point.

Why is H2O considered a polar molecule?

• Because it has a linear shape.

• Because the oxygen atom has a greater attraction for electrons.

• Because it has an equal charge distribution.

• Because it cannot dissolve ionic substances.

What is the main reason for the solubility of substances in water?

• The attraction of the ions to each other within the solid.

• The attraction of the ions to water molecules.

• The attraction of the ions to nonpolar substances.

• The attraction of the ions to air molecules.

Which of the following is an example of a strong electrolyte?

• Ethanol (C2H5OH)

• NaCl

• Sugar (C12H22O11)

• Water (H2O)

What is the definition of a solute in a solution?

• The substance doing the dissolving.

• The substance being dissolved.

• The homogeneous mixture.

• The solvent in which water is the solute.

Which type of solution conducts electricity very efficiently?

• Strong electrolytes

• Weak electrolytes

• Nonelectrolytes

• Nonpolar solutions

What happens to strong acids when dissolved in water?

• They produce OH- ions.

• They do not ionize.

• They produce H+ ions.

• They form nonpolar bonds.

Which of the following is an example of a weak acid?

• BaF₂

• NH₃

• HC₂H₃O₂

• C₂H₅OH

What is the definition of molarity (M)?

• moles of solute per volume of solution in liters

• grams of solute per volume of solution in liters

• moles of solute per volume of solvent in liters

• grams of solute per volume of solvent in liters

What is the molarity of a solution if 500.0 g of potassium phosphate (K₃PO₄) is dissolved in 1.50 L of solution? (Molar mass of K₃PO₄ = 212.27 g/mol)

• 1.57 M

• 2.35 M

• 0.75 M

• 3.00 M