Chapter 2 matter

Question 1

5. When 2 or more substances are physically combined, the result is an ______.

Answer 1

Mixture

U2 C1

Question 2

16. Increasing the surface area of a solid_________.

Answer 2

Increases the speed of dissolving.

U2 C4

Question 3

47. At what temperature is the solubility of KBr the same as that of KNO3?

Answer 3

The intersection is at about 35 degrees Celsius

U2 C4

Question 4

54. List the three points in the kinetic-molecular theory.

Answer 4

• all matter is made of particles
• particles are in constant random motion
• particles collide with each other + the container they are in

U2 C3

Question 5

56. A piece of wood that measures 3cm by 6cm by 4cm has a mass of 80g. A) What is the density of the wood? Circle (A; B) If the density of water is 1 g/ml, would the wood float in water? Explain.

Answer 5

V= 3x6x4=72cm cubed
M= 80g
D= ?
D= m/v
Solve; d= 80/72
D= 1.11g/ml
It would not float because it’s density is greater that waters density.
U2 C2

Question 6

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

Answer 6

• H+ of water attracts 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