Test - Unit 2 Matter

Question 1

16. Increasing the surface area of a solid ______.

Answer 1

A - increases the speed of dissolving

Unit 2 Concept 4

Question 2

52. Bose-Einstein condensates are used to simulate conditions in a ______.

Answer 2

black hole

Unit 2 Concept 3

Question 3

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

Answer 3

1. smaller solute particles - increases the surface area on the solute so the solvent has more places for contact
2. heating - increasing the temperature increases the kinetic energy of the particles, therefore more collisions
3. stirring - brings fresh solvent into contact with undissolved solute
   Unit 2 Concept 4

Question 4

58. A graduated cylinder has 33.5 mL of water. A piece of metal is added to the water and the new volume is now 46.2 mL. If the metal has a mass of 16.25 g, what is its density?

Answer 4

given - Vi = 33.5 mL Vf = 46.2 mL

Unit 2 Concept 2

Question 5

60. Explain how salt dissociates in water. (be specific)

Answer 5

The process in which ionic compounds (salts, crystals) separate into ions, usually in a reversible manner. Positive ends of water attract to negative ions of salt. Negative ends of water attract to positive ions of salt. Attractive force pulls ions away from the crystal. Water molecules surround the ions and continues until all ions are separated.
Unit 2 Concept 4