mock rev - equations

Question 1

equation linking moles, mass and Mr

Answer 1

moles = mass / Mr

Question 2

general formula for alkanes

Answer 2

CnH2n+2

Question 3

general formula for alkenes

Answer 3

CnH2n

Question 4

colour and state of chlorine at room temp

Answer 4

yellow/green gas

Question 5

colour and state of bromine at room temp

Answer 5

red/brown liquid

Question 6

colour and state of iodine at room temp

Answer 6

grey solid

Question 7

colour of bromine solution

Answer 7

orange

Question 8

colour of iodine solution

Answer 8

brown

Question 9

test for alkenes vs alkanes

Answer 9

bromine water reacts with alkenes, go from orange to colourless

Question 10

equation linking moles, concentration and volume

Answer 10

moles = conc x volume (dm3)

Question 11

conversion between cm3 and dm3

Answer 11

1dm3 = 1000cm3

Question 12

how to calculate moles of gas if volume is known

Answer 12

moles = vol (dm3) / 24

Question 13

define ionic bond

Answer 13

the electrostatic attraction between oppositely charged ions

Question 14

define covalent bond

Answer 14

the electrostatic attraction between two nuclei and shared pair of electrons

Question 15

define metallic bond

Answer 15

The electrostatic attraction between positive ions and a sea of delocalised electrons

Question 16

what types of elements are ionically bonded

Answer 16

metals + non-metals

Question 17

what types of elements are covalently bonded

Answer 17

non-metal + non-metal

Question 18

what types of elements are metalically bonded

Answer 18

metals

Question 19

how to do water of crystallisation questions

Answer 19

Step 1: Work out the mol of unhydrated salt
Step 2: Work out the mol of water (can figure out mass by mass lost)
Step 3: Find the mol ratio of unhydrated salt:water (tips: Divide the both number with smaller number)

Question 20

define homologous series

Answer 20

a family of molecules with similar chemical properties, the same general formula and the same functional group

Question 21

define hydrocarbon

Answer 21

an organic compound that contains carbon and hydrogen only

Question 22

define functional group

Answer 22

the group of atoms that control and compound’s chemical properties

Question 23

what are the reactants and products of catalytic cracking

Answer 23

long chain alkane –> alkene + shorter chain alkane

Question 24

catalysts used in cracking

Answer 24

silica or alumina

Question 25

temp range needed for cracking

Answer 25

600-700 C

Question 26

when would u use ‘electrostatic forces of attraction’

Answer 26

applies to all types of bonds, because they’re all EFOA between something positive and negative

Question 27

when would u use ‘intermolecular forces of attraction’

Answer 27

only for simple covalent structures, they’re the only ones with bonds within

Question 28

when would u use ‘forces of attraction’

Answer 28

only when talking abt graphite: layers slide over each other due to weak forces of attraction

Question 29

test for ammonia

Answer 29

turns damp red litmus paper blue

Question 30

test for chlorine

Answer 30

bleaches damp blue litmus paper

Question 31

test for water

Answer 31

turns anhydrous copper sulphate from white to blue