Chemistry Test

Question 1

combustion reaction

Answer 1

substance + O2 > product + H2O (g)

Question 2

neutralisation

Answer 2

acid + base > salt (acid a, base c) + water

Question 3

decomposition

Answer 3

one reactant > 2 products
e.g. H2CO3 > H2O + CO2

Question 4

combination

Answer 4

2 reactants > 1 product
e.g. 2H2 + O2 > 2H2O

Question 5

precipitation

Answer 5

(aq) + (aq) > (aq) + [(aq) or (s)]

Question 6

corrosion

Answer 6

metal + O2 + H2O > metal oxide (e.g. rust)

Question 7

acids + metal

Answer 7

acid + metal > salt + H2

Question 8

acid + carbonate

Answer 8

acid + metal carbonate > salt + H2O + CO2

Question 9

exothermic reaction

Answer 9

releases energy (hot) e.g. fireworks, explosions, bunsen burners

Question 10

endothermic reaction

Answer 10

absorbs energy (cold) e.g. cold packs

Question 11

carbon dioxide

Answer 11

CO2

Question 12

hydrochloric acid

Answer 12

HCL

Question 13

sulfuric acid

Answer 13

H2SO4

Question 14

nitric acid

Answer 14

HNO3

Question 15

sodium hydroxide

Answer 15

NaOH

Question 16

aqueous (aq)

Answer 16

dissolves in water (solution)

Question 17

conservation of mass

Answer 17

during a chemical equation, atoms cannot be created nor destroyed

Question 18

acids

Answer 18

substances which ionize in water to produce H+ ions

Question 19

strong vs weak acids

Answer 19

strong - acids produce lots of H+ ions
weak - acids produce not many H+ ions

Question 20

bases

Answer 20

substances which produce OH- ions

Question 21

strong vs weak bases

Answer 21

strong - bases produce lots OH- ions
weak - produce not not many OH- ions

Question 22

PH scale

Answer 22

measures concentration of H+ ions from 0-14
acidic - PH less than 7
neutral - PH of 7
basic - PH more than 7

Question 23

indicator

Answer 23

substances that change colours at different PHs
- determines approx PH of solutions

Question 24

litmus

Answer 24

indicator
- acidic = red
- basic = blue

Question 25

nuclear decay

Answer 25

the nucleus of an atom releases energy or particles

Question 26

types of nuclear decay

Answer 26

• alpha (α)
• beta (β)
• gamma (γ)

Question 27

alpha decay

Answer 27

• atom emits alpha particle (2p, 2n) from its nucleus
• heavy and slow

Question 28

beta decay

Answer 28

• atom ejects a beta particle (an electron) from its nucleus
• very light and high-speed
• turns neutron into proton > changes element

Question 29

gamma decay

Answer 29

• atom does not eject a particle, ejects a very high energy form of light
• very dangerous and powerful

Question 30

electromagnetic radiation scale

Answer 30

low radiation -> high radiation

Question 31

nuclear charge table

Answer 31

alpha: +2
beta: -1
gamma: 0

Question 32

half life

Answer 32

• the rate that a radioisotope undergoes nuclear decay
• time taken for half of the radioactive atoms to decay