C17 GROUP 7 - HALOGENS

Question 1

what is the test for chlorine and what colour does it turn?

Answer 1

• damp blue litmus paper
• blue, red, bleaches white

Question 2

what is the product of chlorine and sodium?

Answer 2

sodium chloride

Question 3

what is the product of hydrogen and a halogen?

Answer 3

hydrogen halide

Question 4

what is the product of hydrogen and chlorine?

Answer 4

hydrogen chloride

Question 5

what are some uses of chlorine

Answer 5

• disinfectants and bleaches
• treating water for drinking and swimming
• kills bacteria

Question 6

why is group 7 reactive?

Answer 6

they want to gain 1 electron to have a stable outer shell

Question 7

what is electronic configuration?

Answer 7

the arrangement of electrons in an atom

Question 8

what happens to the atoms as you go down group 7?

Answer 8

• atoms get larger
• there are more shells and more shielding
  -elements are less reactive
• shorter half-life

Question 9

what happens to colours of elements as you go down group 7?

Answer 9

colours get darker

Question 10

explain the states of matter of the elements in group 7 at room temperature

Answer 10

higher in the group (i.e. fluorine and chlorine) = gas/liquid at room temperature
lower in the group (i.e. iodine)
= solid at room temperature

Question 11

are group 7 elements diatomic molecules?

Answer 11

yes

Question 12

what is a diatomic molecule?

Answer 12

molecules composed of two atoms

Question 13

what colour is fluorine + state

Answer 13

pale yellow gas

Question 14

what colour is chlorine + state

Answer 14

yellow/ green gas

Question 15

what colour is bromine + state

Answer 15

red/brown liquid

Question 16

what colour is iodine + state

Answer 16

grey/purple solid

Question 17

what is the meaning of deposition?

Answer 17

changing state from a gas to a solid without being a liquid

Question 18

what is the meaning of sublimation?

Answer 18

changing state from a solid to a a gas without being a liquid

Question 19

why are halogens less reactive as you go down the group?

Answer 19

• halogens have 7 outer shell electrons, meaning they want to gain an electron
• as the distance between the nucleus and outer shell increases, there is less forces of attraction between the 2, meaning it is harder to gain another electron
• it is more difficult to form a negative ion

Question 20

what is a displacement reaction?

Answer 20

when a more reactive element displaces (takes the place of) a less reactive element from its compound

Question 21

what is the word equation for the reaction of lithium and iodine?

Answer 21

lithium iodide

(metal halide)

Question 22

what is the word equation for the reaction of hydrogen and chlorine?

Answer 22

hydrogen chloride

(hydrogen halide)

Question 23

what is formed when a hydrogen halide dissolves in water?

Answer 23

acidic solutions

hydrogen bromide dissolved in water = hydrobromic acid

Question 24

what is sublimation?

Answer 24

to go from a solid to a gas without being a liquid

Question 25

what is deposition?

Answer 25

to go from a gas to a solid without being a liquid

Question 26

Why do halogens react readily with metals?

Answer 26

- halogens have seven electrons in their outer shell and need to gain one electron to become stable - metals lose electrons easily, allowing them to form stable ionic compounds with halogens

Question 27

What type of bonding is present in metal halides?

Answer 27

ionic (metal transfers electron to a non-metal)

Question 28

what is formed when hydrogen reacts with fluorine?

Answer 28

hydrogen fluoride

Question 29

Why do halogens readily react with hydrogen?

Answer 29

they need to gain one electron to complete their outer shell

Question 30

What is the name and colour of the only liquid halogen?

Answer 30

bromine and brown

Question 31

What does chlorine look like?

Answer 31

pale green gas

Question 32

How is iodine different to chlorine?

Answer 32

- solid and darker -black in colour

Question 33

Name the compound formed when hydrogen reacts with chlorine

Answer 33

hydrogen chloride

Question 34

What is a displacement reaction?

Answer 34

when a more reactive element takes the place of a less reactive element from its compound eg. chlorine + sodium iodide -> iodine + sodium chloride

Question 35

define diatomic molecule.

Answer 35

two atoms held together by a single covalent bond

Question 36

T or F? halogens are toxic and corrosive

Answer 36

true

Question 37

are halogens metallic or non-metallic elements?

Answer 37

non-metallic

Question 38

T or F? halogens are good conductors of heat and electricity

Answer 38

false halogens are poor conductors of heat and electricity

Question 39

What pattern is there in the depth of colour of halogens?

Answer 39

the particles of halogens of a darker colour are closer together

Question 40

what is formed when a halogen reacts with a metal?

Answer 40

an ionic compound (salts)

Question 41

what does the product of a halogen reacting with a metal also contain?

Answer 41

halide ions