chem paper 2 2021

Oil contains carbon and some sulfur.

When oil is burned, the products of combustion may be released into the atmosphere.

Explain the environmental effects of releasing these products of combustion into the atmosphere.

carbon dioxide produced

• greenhouse gas

• traps heat in the atmopshere

• surface temperature increases

• global warming

• ice caps melt

• rising sea levels

• famine / drought

sulfur dioxide:

• acid rian

• damage to buildings

• d amage to trees

• damage to aquatic animals

• respitory problems in humans

carbon / soot produced

• particulates

• cause global dimming

• respitory problemts in humans

carbon monoxide:

• toxic gas

solar energy may not be able to replace the generation of electriicty to fossil guels completely

suggest two reaosns why

1. unreliable

2. lack of space

whats the formula of Rf value

substance / solvent

Plan an investigation to determine the Rf value for the dye in this food colouring.

Your plan should include the use of:

• a beaker

• a solvent

• chromatography paper.

1. draw pencil start line on chromatography paper

2. pkace spot of food colouring on start line

3. place solvent in beaker

4. place chomatography paper in beaker so that its in solvent

5. the solvent should be below the start line

6. use a lid

7. wait for sovlent to travel up the chromatohgraphy paper to the top

8. dry the chromatogrpahy apper

9. measure distance between start line and centre of spot

10. measure distance between start line and solvent front

11. use measurements to determine Rf value

the Rf value for the same dye were different

how did the students investigations differ

different legnth of paper

different period of time

different size of beaker

different sovlent used

different solvent used

poly(ethene) is a thermosoftenning polymer

suggest why poly(ethene) is easier to recycle than thermosetting polymers

polyethen melts

so can be reshaped into new products

ethen produces different forms of poly(ethene)

how can different forms of poly(ethene) be produced form ethene

use different reaction conditions

which two compounds contain two of these elemnts

• ammonium nitrate

• ammonium phosphate

• potassium chlroide

• calcium phosphate

• potassium nitrate

ammonium phosphate

potassium nitrate

Rocks containing calcium phosphate are treated with acid to produce soluble salts that can be used as fertilisers.

Name the soluble salts produced when calcium phosphate reacts with: • nitric acid

• phosphoric acid.

nitric acid - calcium nitrate

phosphoric acid - calcium dihydrogenphosphate

suggest one reason why solders B and C have different melting properties

the properties of both metals are different

suggest three reasons why recycling scrap copper is a more sustainable way of obtaining copper rather than porcessing copper ores

recycling uses less energy

recycling reudces waste

mining causes environemntal impacts

explain why the line of best fit becomes horizontal

reaction has stopper

because a reactant has been used up

how does figure 9 show that zinc powder reacts more slowly

the line is less steep

the activation energy for reaction between zinc and sulfuric acid is lowered if a solution containing metal ions is added

whats the formula ofr metal ions added

Cu2+