C7 Revision Questions
C7.1
1) Explain the difference between fine and bulk chemicals.
2) Give 4 examples of large scale chemicals and 3 examples of small scale chemicals.
3) Why do companies employ chemists?
4) Give an example of how new chemical products use research and development.
5) How do governments control chemical processes and transport of chemicals?
6) Give the 5 stages of synthesis of chemicals.
7) Give the 7 stages of judging the sustainability of a process.
8) What is meant by the term activation energy?
9) How does a catalyst work?
10) How does the use of enzymes restrict the conditions available for a chemical reaction?
11) Use the Periodic Table to calculate the formula mass of CuSO4.
12) Calculate the mass of CuSO4 obtained from 300g of CuO which reacts with excess H2SO4.
C7.2
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What are hydrocarbons?
Write the formula for a) methane b) ethane c) propane and d) butane.
Draw ball and stick diagrams of the above molecules.
What do hydrocarbons form when combusted?
Why are alkanes unreactive?
Explain the difference between saturated and unsaturated hydrocarbons.
Write a word equation for the reaction between methane and oxygen.
Write a symbol equation for the above reaction and describe how many of each type of
atom and molecule there are.
9) Write a balanced chemical equation with state symbols for the reaction between ethane
gas and oxygen.
10) Draw the structural formula of methanol and ethanol
11) Give two uses of methanol and two uses of ethanol.
12) What is the general formula of alcohols?
13) What is the functional group of alcohols?
14) Compare the boiling points of ethanol, water and ethane.
15) Why do alcohols burn in air?
16) Compare the reactions of ethanol, water and alkanes with sodium.
17) Why is there a limit to the concentration of ethanol made by fermentation?
18) What is distillation?
19) What are the optimum conditions for fermentation?
20) How is waste biomass made into ethanol?
21) How is ethanol made synthetically?
22) Compare the sustainability of fermentation, genetically modified bacterial ethanol and
synthetic ethanol.
23) What is the functional group of carboxylic acids?
24) Draw the structural formula of methanoic acid and ethanoic acid
25) Give the general formula of carboxylic acids
26) Give two examples of smells of tastes of carboxylic acids.
27) Describe how carboxylic acids react with metals, alkalis and carbonates.
28) What is vinegar?
29) Why are carboxylic acids weak?
30) How does the p H of dilute solutions of weak acids compare to those of strong acids?
31) How are esters made?
32) Complete the following sentence: Esters have distinctive……….
33) What are responsible for smells and flavours of fruits?
34) Give 4 uses of esters
35) What are the 2 reagents needed to make an ester?
36) Describe the 4 stages in manufacturing an ester.
37) What are fats?
38) Why do living organisms make fats?
39) Are animal fats or vegetable oils saturated?
C7.3
1) Explain the terms exothermic and endothermic.
2) Draw an energy level diagram for an a) exothermic reaction and an b) endothermic
reaction
3) Describe the energy changes when bonds are broken and when they are made.
4) Calculate the overall energy change for the reaction below:
X2 + Y2 → 2XY given X-X =430kJ/mol, Y-Y = 400 kJ/mol and X-Y = 200 kJ/mol
5) What is meant by the term activation energy?
C7.4
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What is meant by a reversible reaction?
What is meant by a state of equilibrium?
Explain what a dynamic equilibrium is
Why is the Haber Process important?
What are the feedstocks for the Haber Process and what are the raw materials?
a) What type of reaction is the Haber process?
b) How is the yield of the Haber process increased?
c) What are the conditions for the Haber Process?
d) Why don’t the gases reach equilibrium?
e) Why is a catalyst used?
f) How can the efficiency of the process be improved?
g) Why are the conditions a compromise?
7) How do living organisms fix nitrogen?
8) Why do chemists want to mimic natural enzymes?
9) How does the Haber Process affect the environment?
10) Compare the sustainability of the Haber Process and nitrogen fixing organisms.
C7.5
1) Describe the difference between qualitative and quantitative methods of analysis.
2) What must the sample represent?
3) How are most of the samples prepared?
4) Why are standard procedures used?
5) What is chromatography?
6) What are aqueous and non-aqueous solvents?
7) Explain dynamic equilibrium in terms of chromatography.
8) Why do components in chromatography separate?
9) What is standard reference material?
10) Compare and contrast paper and thin layer chromatography.
11) Write down the formula of the Rf value
12) What are locating agents used for?
13) Describe how gas chromatography works.
14) What is meant by the retention time?
15) Draw a graph showing the retention time of two components one of two seconds,
the other of 5 seconds. What do the peak heights mean?
16) Describe the 6 main stages of quantitative analysis.
17) How are concentrations of solutions measured?
18) Describe how to make up a standard solution
19) Calculate the concentration of a solution given 50g of NaCl is dissolved in 400cm3 of
water.
20) Calculate the mass of solute required to make 500cm3 of a solution of 5g/dm3.
21) Describe how to carry out a titration
22) 60 of a 10g/dm3 solution of NaOH is neutralised by 30 cm3 of a solution of HCl. What
is the concentration of HCl in g/dm3?
23) 25cm3 of a 4g/dm3 solution of NaOH is neutralised by 10 cm3 of a solution of HCl.
What is the concentration of HCl in g/dm3?
24) Three titrations gave readings of 10.10, 12.20 and 10.30 which readings would you
use to calculate the average reading?