Some Exam Qs

Question 1

Answer 1

Question 2

Ethanol can also be produced by fermentation.

Describe how ethanol can be produced from sugar by fermentation

Answer 2

• dissolve sugar in water /sugar solution (1)
• (add) yeast (1)
• warm / any temperature or
range within 15 to 40oC (1)
• anaerobic / {no/little} {air/oxygen} c enter the apparatus (1)

Question 3

Describe what you would see when a piece of magnesium ribbon is added to dilute ethanoic acid.

Answer 3

effervescence/fizzing/bubbling
(1)
 solid disappears (1)
 colourless solution (1)

Question 4

Describe what you would see when solid sodium carbonate is added to dilute ethanoic acid.

Answer 4

effervescence / fizzing / bubbles of gas (1)

• solid {disappears/clears} /(colourless)solution formed (1)

Question 5

Answer 5

Question 6

Explain how soap anions remove grease marks from clothes during washing with water.

Answer 6

tail / {hydrophobic / hydrocarbon } end into grease (1)
 head / {anion / hydrophilic} end into water (1)
 allows grease to mix with water when surrounded by soap (anions) / grease is surrounded by soap (1)
 surface tension lowered (1)

Question 7

Answer 7

Question 8

Answer 8

when the decane is heated it
vaporises/turns to a gas (1)
• decane vapour/gas breaks down as it comes in contact with hot porous pot
(1)
• large molecules of decane produce
smaller molecules, including ethene (1)