(a) (i) Define the term fermentation
(ii) Name the catalyst that can be used for this process
(b) Name two factors which determine the choice of an indicator for an acid-base titration
(c) Consider the following reaction equation: Fe + H\(_2\)SO\(_4\) \(\to\) FeSO\(_4\) + H\(_2\). Calculate the mass of unreacted iron when 5.0g of iron reacts with 10cm\(^3\) of 1.0 moldm\(^3\) H\(_2\)SO\(_4\), [Fe = 56.0]
(d) Name one:
(i) Heavy chemical used in electrolytic cells
(ii) Fine chemical used in textile industries
(e) Explain briefly how a catalyst increases the rate of a chemical reaction.
(f) (i) Write the chemical formula for the product formed when ethanoic acid reacts with ammonia
(ii) Give the name of the product formed in (f)(i)
(g) List three properties of aluminum that makes it suitable for the manufacture of drinks cans
(h) State two industrial uses of alkylalkanoates
(i) Name two steps involved in the crystallization of a salt from its solution
(j) List two effects of global warming
(a)(i) Fermentation is the slow breakdown of complex organic substances (especially carbohydrates/sugars) into simpler substances such as ethanol and carbon(IV) oxide by enzymes produced by micro-organisms.
(a)(ii) The enzyme zymase (from yeast).
(b) The choice of indicator depends on: (1) the strengths of the acid and base being titrated (i.e. the type of titration), and (2) the pH range at which the indicator changes colour, which must match the pH at the equivalence point.
(c) Mass of unreacted iron
\( n(\text{H}_2\text{SO}_4) = 1.0 \times \dfrac{10}{1000} = 0.01\ \text{mol} \)
Fe + H2SO4 \(\to\) FeSO4 + H2 (1 : 1), so Fe reacting = 0.01 mol.
Mass of Fe reacted = \(0.01 \times 56 = 0.56\ \text{g}\).
\[ \text{Unreacted Fe} = 5.0 - 0.56 = 4.44\ \text{g} \]
(d)(i) A heavy chemical: sodium chloride (brine) (or sulphuric acid / sodium hydroxide).
(d)(ii) A fine chemical: a dye.
(e) A catalyst provides an alternative reaction pathway with a lower activation energy, so a greater fraction of the colliding particles have enough energy to react, and the rate increases.
(f)(i) \( \text{CH}_3\text{COONH}_4 \)
(f)(ii) Ammonium ethanoate.
(g) Aluminium is light (low density), resistant to corrosion (protective oxide layer), and malleable/easily shaped and non-toxic.
(h) Alkylalkanoates (esters) are used as flavourings/perfumes and as solvents.
(i) (1) Evaporate the solution to the point of saturation; (2) cool the hot saturated solution to allow crystals to separate (then filter and dry).
(j) Melting of polar ice caps and rise in sea level, and climate change/flooding (or increased desertification).
(a)(i) Fermentation is the slow breakdown of complex organic substances (especially carbohydrates/sugars) into simpler substances such as ethanol and carbon(IV) oxide by enzymes produced by micro-organisms.
(a)(ii) The enzyme zymase (from yeast).
(b) The choice of indicator depends on: (1) the strengths of the acid and base being titrated (i.e. the type of titration), and (2) the pH range at which the indicator changes colour, which must match the pH at the equivalence point.
(c) Mass of unreacted iron
\( n(\text{H}_2\text{SO}_4) = 1.0 \times \dfrac{10}{1000} = 0.01\ \text{mol} \)
Fe + H2SO4 \(\to\) FeSO4 + H2 (1 : 1), so Fe reacting = 0.01 mol.
Mass of Fe reacted = \(0.01 \times 56 = 0.56\ \text{g}\).
\[ \text{Unreacted Fe} = 5.0 - 0.56 = 4.44\ \text{g} \]
(d)(i) A heavy chemical: sodium chloride (brine) (or sulphuric acid / sodium hydroxide).
(d)(ii) A fine chemical: a dye.
(e) A catalyst provides an alternative reaction pathway with a lower activation energy, so a greater fraction of the colliding particles have enough energy to react, and the rate increases.
(f)(i) \( \text{CH}_3\text{COONH}_4 \)
(f)(ii) Ammonium ethanoate.
(g) Aluminium is light (low density), resistant to corrosion (protective oxide layer), and malleable/easily shaped and non-toxic.
(h) Alkylalkanoates (esters) are used as flavourings/perfumes and as solvents.
(i) (1) Evaporate the solution to the point of saturation; (2) cool the hot saturated solution to allow crystals to separate (then filter and dry).
(j) Melting of polar ice caps and rise in sea level, and climate change/flooding (or increased desertification).
