topic 2

Question 1

what kind of structure do ionic compounds have?

Answer 1

closely packed regular lattice structure

Question 2

ionic bonds have very strong…

Answer 2

electrostatic forces of attraction between oppositely charged ions

Question 3

what are the 2 main properties of ionic compounds?

Answer 3

they have high melting and boiling points

they conduct electricity when aqueous or molten

Question 4

when do inimical compounds conduct electricity?

Answer 4

when aqueous or molten

Question 5

do I ionic compounds have high or low melting and boiling points?

Answer 5

high

Question 6

why do I ionic compounds have high melting and boiling points?

Answer 6

they have strong electrostatic forces of attraction between oppositely charged ions so it takes a lot of energy to break these bonds

Question 7

why do ionic compounds conduct electricity when aqueous?

Answer 7

the ions speedster and are all free to move so they can carry an electrical current

Question 8

what diagrams are used to show inimical compounds?

Answer 8

dot and cross diagram

Question 9

why do ionic compounds conduct electricity when molten?

Answer 9

the ions are free to move so they can carry and electrical current

Question 10

what are the two rules when naming compounds?

Answer 10

1) when two different elements combine the compounds name is something ‘ide’
2) when 3 or more different elements combine and one of the is oxygen the compounds name is something ‘ate’

Question 11

how do you make a pure, dry sample of an insoluble salt?

Answer 11

use a precipitate reaction

Question 12

is barium sulphate an insoluble salt?

Answer 12

yes

Question 13

what are the steps of a precipitation reaction?

Answer 13

1) mix the two solutions together
2) filter out the precipitate
3) wash it with distilled water to wash impurities off the precipitate
4) dry it on filter paper

Question 14

give a use of barium sulphate

Answer 14

x - Rays

barium meal

Question 15

why do we use barium sulphate for x rays?

Answer 15

it is opaque to x rays so when you drink it it shows up the gut so that any problems can be seen

Question 16

barium salts are toxic so why can you safety drink barium sulphate?

Answer 16

it’s insoluble so it isn’t absorbed into the bloodstream

Question 17

what colour flame is:
sodium
potassium
calcium
copper

Answer 17

yellow/orange
lilac
brick-red
blue-green

Question 18

how do you conduct a flame test?

Answer 18

1) dip a clean fire loop into a compound

2) put the wire loop in the clear blue part of the Bunsen flame

Question 19

how do you make sure the wire loop is clean when doings flame test?

Answer 19

dipping it into hydrochloride acid and rinsing it with distilled water

Question 20

what do you do if you’re using a powered solid when doing a flame test?

Answer 20

dip the wire loop in hydrochloric acid to moisten it before dipping it in the solid so that some of the solid sticks to the wire

Question 21

what is a spectroscopy used for?

Answer 21

to identify elements in a sample

Question 22

what are positives of using spectroscopy?

Answer 22

it’s fast, reliable and can be used with vey small amounts of elements in a sample

Question 23

how does a spectroscopy work?

Answer 23

a little like the flame test, the patterns of light emitted by the elects in a heated sample are analysed

Question 24

how do you test for carbonates? testing to see if a gas is carbon dioxide

Answer 24

by bubbling it through limewater and if carbon dioxide is present then the limewater turns milky

Question 25

why can you use the limewater test to test for carbonate ions?

Answer 25

because carbonates react with dilute acids to form carbon dioxide

Question 26

how do you test for sulphate ions?

Answer 26

add dilute hydrochloric acid followed by barium chloride solution and a white precipitate of barium sulphate would be produced if the original compound was a sulfate

Question 27

how do you test for chloride ions?

Answer 27

add dilute nitric acid followed by silver nitrate solution and a white precipice of silver chloride will be formed if chloride is present