chem- physical properties

Question 1

What is a physical property? (GIVE EXAMPLES)

Answer 1

a property that can be observed with the senses, and can be determined without destroying the object (ex. colour, mass, hardness, melting/boiling point, conductivity)

Question 2

What is a chemical property? (GIVE EXAMPLES)

Answer 2

is the ability of a substance to chemically react to form new substances, must undergo a chemical change in order to be observed (ex. combustibility, reaction with acid/base)

Question 3

What is a physical change? (GIVE EXAMPLES)

Answer 3

Name of substance does not change, it’s just in a different form or state, may have new properties, but particles are the same. (ex. ice melting, ripping paper)

Question 4

What is a chemical change? (GIVE EXAMPLES)

Answer 4

A new substance with new properties is formed. May be difficult or impossible to reverse. Masses may change, total mass does not. (ex. burning wood, metal + HCl)

Question 5

Name 5 signs of a chemical change

Answer 5

bubbles, precipitate, color change, temperature change, light emitted, volume change, conductivity change, melting/boiling point change, smell or taste change, change in any definining chemical or physical property of a substance

Question 6

what are 3 properties of solid matter?

Answer 6

definite shape and volume, temperature and pressure have little effect, not easily compressed

Question 7

what are 3 properties of liquid matter?

Answer 7

definite volume, no definite shape (takes shape of any container), may be compressed slightly, particles can slide past each other easily

Question 8

what are 3 properties of gas matter?

Answer 8

no definite volume or shape (fills any space), temperature and pressure have large effect, highly compressible

Question 9

what is plasma? (give examples)

Answer 9

a gaseous mixture of positive ions and electrons (ionized gas), very hot (>1million degrees C), low density, compressible, expand to fill container (ex. stars, lightning)

Question 10

what is the most abundant state of matter in the universe?

Answer 10

plasma (99%) (even tho its the least abundant on earth)

Question 11

what is a liquid crystal

Answer 11

a liquid with organized molecules

Question 12

what is an amorphous material

Answer 12

a substance with an irregular particle arrangement and no definite melting point. (ex. peanut butter, wax, plastic, glass)

Question 13

what are the 6 molecular properties of gases?

Answer 13

1. gas has mass
2. gasses are compressible
3. gases fill their container
4. gases diffuse through each other easily
5. gases exert pressure
6. pressure of a gas depends on temperature

Question 14

why do gases have pressure?

Answer 14

particle motion results in collisions with the container

Question 15

what is an elastic collision (give an example)

Answer 15

no energy lost, ex. gas colliding with container (this allows constant pressure under constant temperature)

Question 16

do gases have intermolecular forces?

Answer 16

no

Question 17

what are intermolecular forces?

Answer 17

forces between molecules beside each other, much weaker than a covalent bond

Question 18

what effects do temperature and IMFs have on viscosity of a liquid?

Answer 18

temp up v down, IMF up v up

Question 19

what are the 4 types of crystalline solids? (give examples)

Answer 19

covalent network- single element, very strong, ex. diamond, graphite, silicon
ionic solids- ions arrange themselves in an alternating pattern, very stable, ex. NaCl, CaF2
Molecular solids- held together by IMFs, usually soft, ex. I2, S8
Metallic solids- atoms held together by valence electrons, varying strength, ex. copper, silver, lead

Question 20

are IMFs stronger or weaker than ionic bonds?

Answer 20

weaker

Question 21

are IMFs between covalent molecules stronger or weaker than those between ionic particles?

Answer 21

weaker

Question 22

what happens when you boil a liquid in a sealed container

Answer 22

liquid and gas in dynamic equilibrium (no net change, vaporization and condensation happening at the same rate)

Question 23

What are sublimation and deposition? give examples

Answer 23

s- solid to gas ex. dry ice, air freshner
d- gas to solid ex. frost

Question 24

explain why sweating works

Answer 24

vapourization is endothermic, the process requires energy, therefore the evaporating sweat molecules take heat from the environment with them.