Energtics

Question 1

Pure vanadium for nuclear reactors is formed by the reaction of hydrogen with purified vcl2

Write an equation for this reaction where the only other product is HCL

Identify two hazards in this process, other than the fact it operates a high temperature

Deduce why this process produces pure vanadium other than the fact that purified vcl2 is used

Answer 1

Vcl2 + h2 > v + 2HCl
( when it says write equation then balance it)

Two hazard
H2 is flammable
HCL is toxic

HCL is easily removed

Question 2

Explain why cf4 has a bond angle of 109.5

Answer 2

Because the central atom c is attracted to 4 bonding pairs electrons that repel equally and spread out as far as possible

Question 3

Antimony sulfide (sb2 s3 ) is roasted in the air to convert into sb2O3 and sulfur dioxide 

Write an equation for this reaction

Identify one substance that is manufactured directly from sulphur dioxide formed in this reaction 

Answer 3

Sb2S3 + 4.5O2 > sb203 + 3so2

Sulphuric acid or s(VI)oxide

Question 4

Deduce one reason why the method of extraction from a low grade ore is a low cost process

Answer 4

Uses low temperature

Question 5

Suggest one improvement that will reduce errors due to heat loss in the students experiment 

Answer 5

Adding a lid so it’s a closed system

Question 6

Play, my calcium has a higher, melting point then strontium 

Answer 6

Calcium has stronger melting bonding as the delocalised electrons are closer to cations

Question 7

Write an equation for the reaction of magnesium with oxygen

Write an equation for the reaction of magnesium with cold water

Give the given medical use for the magnesium compound formed in the reaction of magnesium with cold water 

Answer 7

2mg + O2 > 2mgO as metal plus oxygen makes metal oxide

Mg + 2H2O > mgoh2 + h2 metal plus water makes metal hydroxide and hydrogen

Magnesium hydroxide can be used to neutralise stomach acid