CSEC Chemistry Paper 2 May/June 2015 - Free CXC Past Paper with Answers

(b)(i)

Use the readings shown in Figure 2 to complete Table 1.

TABLE 1: READINGS FROM FIGURE 2


Mass of conical flask and water (g)
Mass of conical flask (g)
Mass of water used (g)
Final temperature of water ( $^\circ$ C)
Initial temperature of water ( $^\circ$ C)
Temperature change ( $^\circ$ C)
Initial mass of candle and watch-glass (g)
Final mass of candle and watch-glass (g)
Mass of candle burnt (g)

[9 marks]

(c)

A student carried out a number of tests on a solid mixture labelled Q. Some of the observations and inferences are recorded in Table 2. Complete the table by inserting the observations or observations as necessary.

TABLE 2: OBSERVATIONS AND INFERENCES

Test	Observation	Inference
(i) Q is heated strongly in a boiling tube.	Brown fumes are seen around the mouth of the boiling tube.	•
	The gases evolved are bubbled into aqueous calcium hydroxide.	The glowing splint is rekindled.
		A white precipitate is formed.
(ii) Dilute HCl is added in excess to Q and the mixture warmed. To the resulting solution, aqueous NaOH is added until in excess.	A green precipitate is formed which is insoluble in excess NaOH.	•
(iii) Dilute nitric acid followed by a few drops of silver nitrate solution was added to Q.	•	Cl $^{-}$ ions present
The test tube was left standing in light for 5 minutes.	•
Ammonium hydroxide was then added to the resulting mixture.	•

[25 marks]

(c)(i)

Use the readings shown in Figure 2 to complete Table 1.

TABLE 1: READINGS FROM FIGURE 2

[9 marks]

(c)(ii)

Dilute HCl is added in excess to Q and the mixture warmed. To the resulting solution, aqueous NaOH is added until in excess.

Test	Observation	Inference
	A green precipitate is formed which is insoluble in excess NaOH.

(Ionic equation required)

[2 marks]

(c)(iii)

Complete the table by inserting the observations or inferences as necessary.

TABLE 2: OBSERVATIONS AND INFERENCES

Test	Observation	Inference
Dilute nitric acid followed by a few drops of silver nitrate solution was added to Q.		Cl $^{-}$ ions present
The test tube was left standing in light for 5 minutes.
Ammonium hydroxide was then added to the resulting mixture.

[3 marks]

Question 3 (15 marks)

The fully displayed structures for two hydrocarbons, Compound A and Compound B, are shown below.

      H   H   H   H
      |   |   |   |
H --- C - C - C - C --- H
      |   |   |   |
      H   H   H   H

Compound A

      H   H   H   H
      |   |   |   |
H --- C = C - C - C --- H
      |       |   |
      H       H   H

Compound B

[15 marks]

(a)

The fully displayed structures for two hydrocarbons, Compound A and Compound B, are shown below.

      H
      |
H-C-C-H
| | |
H H H H

Compound A

      H H H H
      | | | |
H-C-C=C-C-H
      | |
      H H

Compound B

(a)(i)

Name the homologous series to which Compounds A and B belong.

Compound A: Compound B:

[2 marks]

(a)(ii)

State the name of EACH compound.

Compound A: Compound B:

[2 marks]

(b)(i)

Define 'structural isomerism'.

[2 marks]

(b)(ii)

Draw the FULLY DISPLAYED structure of ONE structural isomer for EACH of Compounds A and B.

[4 marks]

(c)

Polythene is manufactured in Trinidad and is used extensively throughout the Caribbean.

[7 marks]

(c)(i)

Define the term 'polymer'.

[1 mark]

(c)(ii)

Identify the type of polymerization that is used in the manufacture of polythene.

[1 mark]

(c)(iii)

State TWO uses of polythene.

[2 marks]

(c)(iv)

State the name of ONE other polymer.

[1 mark]

Question 5 (15 marks)

Figure 3 is a flow diagram of the industrial processing of sugar cane to produce crystalline sucrose. Study the figure carefully and answer the questions which follow.

Figure 3. Industrial processing of sugar

                  SUGAR CANE
                      |
                      v
                  MILL TRAIN
                  /        \
                 v          v
               JUICE      BAGASSE
                 |
                 v
              Process P
                 |
                 v
             FILTRATION
                 |
                 v
              Process Q
                 |
                 v
           CENTRIFUGATION
             /          \
            v            v
          Sugar      Product X

[2 marks]

(a)

Figure 3 is a flow diagram of the industrial processing of sugar cane to produce crystalline sucrose. Study the figure carefully and answer the questions which follow.

Figure 3. Industrial processing of sugar

(a)(i)

Identify Process P and Process Q.

Process P: Process Q:

[2 marks]

(a)(ii)

State the importance of the centrifugation process.

[1 mark]

(a)(iii)

Identify Product X.

[1 mark]

(a)(iv)

The bagasse produced is used in the factory during the processing of sugar cane. In which part of the factory is this bagasse used and what is it used for?

[2 marks]

(b)

Many Caribbean islands are renowned for the quality of rum they produce. The alcohol content of a typical rum averages between 40% and 55%.

(b)(i)

Many Caribbean islands are renowned for the quality of rum they produce. The alcohol content of a typical rum averages between 40% and 55%.

During the fermentation process in the making of rum, yeast feeds on the sucrose in molasses converting it into simpler sugars which are then converted to ethanol. Outline, using balanced equations, the formation of ethanol from sucrose.

[3 marks]

(b)(ii)

Jemina was presented with a flask that contains a mixture of diluted rum. Draw a labelled diagram of the apparatus she should use in the laboratory to obtain a concentrated sample of ethanol.

Space for diagram

[3 marks]

(c)

After accidentally leaving a bottle of wine open for several days, Jemina found that the wine tasted slightly sour. She was given magnesium oxide to react with a sample of the sour wine.

Suggest the type of reaction that takes place when the magnesium oxide is mixed with the sour wine. Write a balanced chemical equation for this reaction.

[3 marks]

CSEC Chemistry Paper 2 May/June 2015 - Free CXC Past Paper with Answers

CSEC Chemistry Paper 2 May/June 2015 Questions

Question 1 (31 marks)

Procedure:

TABLE 1: READINGS FROM FIGURE 2

TABLE 1: READINGS FROM FIGURE 2

TABLE 2: OBSERVATIONS AND INFERENCES

Question 2 (15 marks)

Question 3 (15 marks)

Question 4 (15 marks)

Question 5 (15 marks)

Figure 3. Industrial processing of sugar

Figure 3. Industrial processing of sugar

Question 6 (15 marks)