chem. unit test

Question 1

cation

Answer 1

positively charged ion

Question 2

anion

Answer 2

negatively charged ion

Question 3

ionic bond

Answer 3

simultaneously strong attraction of positive and negative ions in ionic compound

Question 4

covalent bond

Answer 4

bond that results from the sharing of outer electrons between non-metal atoms

Question 5

decomposition

Answer 5

1 substance breaks apart into 2 or more new substances

Question 6

synthesis

Answer 6

2 or more substances combine to form 1 new product

Question 7

endothermic

Answer 7

reaction is cooler than surroundings

Question 8

exothermic

Answer 8

reaction is warmer than surroundings

Question 9

physical change

Answer 9

when substance changes form but not chemical composition (paper cutting, ice melting)

Question 10

chemical change

Answer 10

substance is altered at molecular level, creating a new chemical (bubbles/fizz, new colour, temp change, precipitate)

Question 11

law of conservation of mass

Answer 11

in any given chemical reaction, the total mass of the reactants equals the total mass of the product

Question 12

corrosion

Answer 12

the breakdown of a metal resulting from reactions with chemicals in its environment

Question 13

galvanized steel

Answer 13

steel that bas been coated with a protective layer of zinc, which forms a hard, insoluble oxide

Question 14

hydrogen test

Answer 14

• lowering burning splint into test tube
• splint pops

Question 15

oxygen text

Answer 15

• lowering a glowing wooden splint into the test tube
• splint re-lights

Question 16

carbon dioxide test

Answer 16

• add limewater into the test tube
• turns cloudy

Question 17

hard or soft?

Answer 17

molecular - soft
ionic - hard

Question 18

buffering capacity

Answer 18

the ability of a substance to resist changes in pH

Question 19

phytoremediation

Answer 19

uses plants to clean up contaminated environments

Question 20

pH scale

Answer 20

numerical scale ranging from 0-14 used to compare the acidity of solutions

Question 21

acids contain

Answer 21

H

Question 22

bases contain

Answer 22

OH

Question 23

acid pH

Answer 23

0-6

Question 24

base pH

Answer 24

8-14

Question 25

neutral

Answer 25

7

Question 26

phenolphathalein

Answer 26

acid - stays white
base - turns pink

Question 27

methyl orange

Answer 27

acid - stays red
base - turns yellow

Question 28

bromthymol blue

Answer 28

acid - stays yellow
base - turns blue

Question 29

reaction with sodium bicarbonate

Answer 29

acid - CO2
base - NA

Question 30

reaction with magnesium

Answer 30

acid - H2
base - NA

Question 31

litmus paper

Answer 31

acid - red
base - blue

Question 32

equation of acid-base neutralizer

Answer 32

acid + base —> salt + water

Question 33

why is calcium oxide capable of neutralizing acids

Answer 33

product is metal hydroxide when reacted with water

Question 34

dissolved in water

Answer 34

molecular - no
ionic - yes

Question 35

electrolytes

Answer 35

molecular - no
ionic - yes

Question 36

odour

Answer 36

molecular - yes
ionic - no

Question 37

melting point

Answer 37

molecular - high
ionic - low