C4.1 - predicting chemical reactions

Question 1

what is another name for Group 1 elements? (and why)

Answer 1

alkali metals, because they react with water to form alkaline solutions

Question 2

state 4 properties of group 1 elements

Answer 2

• solid at room temperature
• can be cut with a knife (soft)
• shiny when freshly cut
• good conductor of electricity

Question 3

how is softness affected as you go down the group 1 elements?

Answer 3

increases

Question 4

what is the trend of density in group 1 elements?

Answer 4

increases (while going down list)

Question 5

what is the trend for melting points of Group 1 elements?

Answer 5

decreases

Question 6

how does reactivity change as you go down the Group 1 elements?

Answer 6

increases

Question 7

how does lithium react with water?

Answer 7

fizzes steadily then slowly disappears

Question 8

how does sodium react with water?

Answer 8

• melts to form a silver ball
• fizzes vigorously
• quickly disappears

Question 9

how does potassium react with water?

Answer 9

• ignites immediately
• lilac flame
• quickly disappears

Question 10

state the word equation of the reaction between Group 1 elements and water

Answer 10

metal + water -> metal hydroxide + hydrogen

Question 11

give the balanced chemical formula (with state symbols) of when sodium reacts with water

Answer 11

2Na (s) + 2H20 (l) -> 2NaOH (aq) + H2 (g)

Question 12

explain the trend of reactivity in Group 1 elements

Answer 12

• reactivity increases
• atoms become larger, and so harder for positive nucleus to attract outer electron (so easier to lose, and therefore react)
• outer electron’s distance from nucleus increases
• shielding (other electrons get in the way)

Question 13

are halogens:

• nonmetals/metals
• brittle/solid
• conduct elecricity well/or not
• exist as mono-atomic/diatomic
• strong intermolecular forces/weak

Answer 13

• nonmetals
• brittle (solid)
• poor conductors of electricity
• exist as diatomic molecules
• weak im forces

Question 14

describe fluorine at room temperature

Answer 14

pale yellow gas

Question 15

describe chlorine at room temperature

Answer 15

green gas

Question 16

describe bromine at room temperature

Answer 16

orange-brown liquid (vaporises easily)

Question 17

describe iodine at room temperature

Answer 17

grey-back solid (sublimes to purple gas)

Question 18

trend of density of group 7 elements?

Answer 18

increases

Question 19

trend of melting/boiling points of Group 7 elements?

Answer 19

increases

Question 20

what is another name for group 7 elements?

Answer 20

halogens

Question 21

trend of reactivity of halogen elements?

Answer 21

decreases

Question 22

do group 7 elements react with group 1 elements?

Answer 22

yes, vigorously

Question 23

how do you explain the trend in reactivity of group 7 elements?

Answer 23

• decreases
• atoms become larger, and so harder for positive nucleus to attract other electrons electron (so harder to gain, and therefore react)
• outer electron’s distance from nucleus increases (so harder to gain electrons)
• shielding (other electrons get in the way) - amplified effect

Question 24

what determines how reactive an element is?

Answer 24

how easily it loses/gains electrons

Question 25

what is a halide?

Answer 25

a compound containing a group 7 element with one other element (hydrogen/metal)

Question 26

how do you determine whether a halogen would displace another halide?

Answer 26

whether it is more reactive or not (or higher on the periodic table)

Question 27

would chlorine displace bromine from bromides?

Answer 27

yes

Question 28

where are the noble gases?

Answer 28

Group 0 (IUPAC group 18)

Question 29

why are noble gases unreactive?

Answer 29

because they have full outer shells (little tendency to lose or gain electrons)

Question 30

state features of noble gases

Answer 30

- conduct electricity - odorless - mono-atomic - gases at room temperature

Question 31

trend of boiling point of noble gases? (and why)

Answer 31

increases (atoms get larger, attractive forces become stronger) - GENERALLY VERY LOW

Question 32

trend of density of noble gases (why)?

Answer 32

increases, larger atoms take up more space in set volume | GENERALLY VERY LOW - in gas state

Question 33

state 4 properties of transition metals

Answer 33

- shiny (when freshly cut) - good conductor of electricity - strong - malleable

Question 34

how do transition metals compare to Group 1 metals (alkali metals)

Answer 34

- stronger + harder - higher density - higher melting point

Question 35

are the transition metals reactive?

Answer 35

not really, react very slowly (if at all)

Question 36

what do gold, platinum and iridium have in common?

Answer 36

do not react with water or oxygen at all

Question 37

are alkali metals coloured in ionic compounds?

Answer 37

(no) colourless

Question 38

are transition metals coloured in ionic compounds?

Answer 38

(yes) coloured

Question 39

are transition metals good catalysts?

Answer 39

yes

Question 40

What’s used for catalytic converters

Answer 40

catalytic converters convert harmful gases in vehicle exhaust fumes into less harmful ones platinum, rhodium and palladium

Question 41

what is necessary for a metal fo react with water or a dilute acid? (reactivity)

Answer 41

for it to be more reactive than hydrogen

Question 42

what is produced when a metal reacts with water?

Answer 42

metal hydroxide + hydrogen

Question 43

what is produced when a metal reacts with a dilute acid?

Answer 43

salt (ie. sodium chloride) + hydrogen

Question 44

how do you put metals into order of reactivity?

Answer 44

- place metal in water/dilute acid | - compared amount of bubbles/hydrogen produced

Question 45

how would reactive non-metals react?

Answer 45

form covalent bonds with each other