Test - Unit 2 Matter

Question 1

16. Increasing the surface area of a solid ____________.

Answer 1

increases the rate of dissolving

U2 C4 Notes p. 33

Question 2

55. List and explain the three factors that increase the solubility (dissolving) rate of a substance.

Answer 2

1. A smaller solute size because it increases the surface area on the solute so the solvent has more places for contact.
2. Heating the solvent because increasing the temperature increases the kinetic energy of the particles, therefore more collisions.
3. Stirring the solution because it brings fresh solvent into contact with undissolved solute.

U2 C3 Notes p. 33

Question 3

56.

Answer 3

Given: V= 3cm x 6 cm x 4cm

Practice- Density Calculations

Question 4

60. Explain how salt dissociates (dissolves in water. Be specific.

Answer 4

• H+ of water attacks Cl–
• O-2 of water attracts Na+
• Attractive force pulls ions away from crystal
• Water surrounds each ion and continues until all ions are separated.

U2 C4 Notes p. 33