Group 2

Question 1

State one method the student could use for removing soluble impurities from the sample of magnesium hydroxide that has been separated

Answer 1

Add a small amount of cold water

Question 2

If there is only one product what is the percentage yield

Answer 2

100 percent

Question 3

What element from mg to ba is the most soluble in water

Answer 3

Barium hydroxide

Question 4

2 observations when magnesium reacts with steam

Answer 4

White light formed

And white precipitate formed

Question 5

You are given a sample of saturated calcium hydroxide solution, outline the practical steps that you would take to determine the solubility of calcium hydroxide in this solution

Answer 5

Take a known volume of the saturated solution evaporate the filter to dryness and weigh the residue.

Question 6

Write an ionic equation to show how calcium reacts w excess water

Answer 6

Ca(s)+2h20(l)—>ca2+(aq) +2OH-(aq)+ H2(g)

Question 7

Magnesium burns with a bright white light, why should water not be used to put out a fire where magnesium is burning

Answer 7

As hydrogen is produced and hydrogen is flammable. As when it reacts w water hydrogen is produced innit alaynah… mg0h+h2

Question 8

What is calcium hydroxide used for

Answer 8

Neutralising acidic soils to help farmers grow plant so like agriculture but also LIME( used for the removal of sulfur dioxide from flue gases)

Question 9

Give the formula of the hydroxide of the element in group 2 that is the most soluble in water

Answer 9

Ba(OH)2

Question 10

Explain why different observations are made when aqueous barium chloride is added separately to aqueous magnesium sulfate and to aq magnesium nitrate

Answer 10

As bas04 is insoluble and no reaction occurs in the second case as barium nitrate remains in a solution so the reactions differ.

Question 11

The equation for extracting titanium using magnesium

Answer 11

TiCl4(l)+Mg(s)—>2MgCl2(g)+Ti(s)

Question 12

Identify a sodium halide that does not undergo a redox reaction when added as a solid to concentrated sulfuric acid

Answer 12

NaF or NaCl

Question 13

Chlorine gas reacts with cold dilute sodium hydroxide to form sodium chloride and another chlorine which one

Answer 13

NaClO

Question 14

Why is it important to clean the surface of magnesium ribbon when investigating its rate of reaction

Answer 14

Bc the mg is coated with an oxide so it has to be removed before it reacts

Question 15

You are given a sample of saturated calcium hydroxide. Outline the practical steps that you would take to determine solubility of calcium hydroxide in this solution

Answer 15

Take a known volume of the saturated solution, evaporate the filtrate to dryness and weigh the residue.

Question 16

Equation for the thermal decomposition of zinc carbonate to zinc oxide

Answer 16

ZnCO3—> ZnO+CO2

Question 17

Magnesium sulfate test w h2so4 and naoh

Answer 17

No visible change w h2so4 and gives white ppt with NaOH

Question 18

Barium carbonate w h2so4

Answer 18

Carbonate ion releases co2 bur baso4 formed highly insoluble

Question 19

The method the scientists used could not detect one type of halide ion. Identify this halide ion

Answer 19

Silver fluoride which is soluble therefore no ppt would for, so no observable change

Question 20

Why is drinking magnesium sulfate effective in the treatment of barium poisoning

Answer 20

Bc it forms insoluble barium sulfate

Question 21

give a medical use for the magnesium compouhnd formed in the reac of magnesium and cold water

Answer 21

magnesium hydroxide, used for treatment of indigestion

Question 22

give the formula of the substance responsible for the orange colour when chlorine is bubbled through an aqueuous solution of sodium bromide

Answer 22

br2

Question 23

solid sodium iodide undergoes a redox reaction with conc sulfuric acid, give the formula of each of the following in this reac. the formula of the solid reduction and oxidation product

Answer 23

s2 red. ox- i2

Question 24

state why sulfuric acid should not be used to acidify bacl when testing for sulfate ions

Answer 24

bc it contains sulfate ions, this would form a white precipitate, false pos

Question 25

pure mg reacts completely with an excess of dilute sulfuric acid, the reaciton of pure calcium with an excess of dilute sulfuric acid is very rapid initially. this reaction slows down and stops before all teh calcium has reacted. why are the reactions different

Answer 25

magnesium sulfate is soluble and calcium sulfate is insoluble so coats the calcium preventing it to react further

Question 26

identify what precipitate does not dissolve in conc ir dilute ammonia

Answer 26

SILVER iodide AgI. not just iodine

Question 27

how to distinguish between silver nitrate and aqueous sodium nitrate

Answer 27

use hcl of course, bc silver nitrate so it will form a white ppt

Question 28

how to distinguish aq magnesium chloride and aq barium chloride

Answer 28

in this case, bc barium chloride. use naso4 or whatever sulfate, and it would form a white ppt with barium chloride

Question 29

what would magnesium sulfate form with NaOH

Answer 29

white precipitate

Question 30

if a hydroxide reacts with a sulfate or sulfuric acid what will form

Answer 30

a sulfate compound which means a white ppt will be observed

Question 31

state one way of removing an aq solution from another one

Answer 31

fractional distillation

Question 32

why would nitric acid be replaced by barium sulfate in a reaction

Answer 32

because barium sulfate is insoluble so easier to remove

Question 33

explain how metals conduct elec

Answer 33

delocalised electrons FLOW in a GIVEN direction

Question 34

if ycl2 forms w white ppt with NaOH what is y

Answer 34

magnesium. bc magnesium turns white w naoh

Question 35

if ycl2 has no ppt what can y be now w naoh

Answer 35

barium bc that wouldnt do anything right bacl

Question 36

why can carbonates not be present in a reac that has been reacted w hno3

Answer 36

bc the carbonates have reacted w the acid

Question 37

what state is mg(oh)2

Answer 37

solid