WHAT YOU MUST KNOW ABOUT CHEMISTRY PAPER 3

JOM KIMIA A1

WHAT YOU MUST KNOW ABOUT CHEMISTRY PAPER 3QUESTION 1

(2008 no. 1)

Diagram 1 shows three sets, Set I, Set II and set III, of the apparatus set-up for an experiment to investigate the effect of ethanoic acid and ammonia solution on the coagulation of latex.

(a) State one hypothesis based on Set I and Set II.

...

[3 marks]

(b)Record the time taken for the latex to coagulate in Set I and Set III.

Set I :.

Set III :....

[3 marks]

(c)Construct a table to record the time taken for coagulation in Set I and Set III.

(d) State one observation that can be obtained from each set of this experiment.

Set I: ....

....

Set II: ....

....

Set III: ....

....

[3 marks]

(e)State the operational definition for the coagulation of latex.

..

..

.

[3 marks]

(f) For this experiment, state:

(i) The manipulated variable : ...

(ii)The responding variable: ...

(iii)The constant variable

: ...

[3 marks]

(g)(i) Excess hydrochloric acids is added to the beaker in Set II after 2:00 pm.

What observation can be made about the latex?

.

.

.

[3 marks]

(ii)Explain the answer in 1(g)(i).

.

.

.

[3 marks]

(h)Explain why latex can coagulate without acid in Set III.

.

.

.

[3 marks]

(i)(i)Explain why the latex in Set I coagulates faster than the latex in Set III.

.

.

.

[3 marks]

(ii)The following is a list of chemical substances:

Nitric acid

Sodium hydroxide

Methanoic acid

Potassium hydroxide

Classify these substances into substances that can coagulate and substances that cannot coagulate latex.

[3 marks]

QUESTION 2(2008 no. 2)The three statements below describe the observation made when three elements react with water. The elements are in Group 1 of the Periodic Table of Elements.

Statement 1

Lithium, Li, moves slowly at random on the surface of the water with a little fizzing.

The water then turns red litmus paper to blue.

Statement 2

Sodium, Na, moves rapidly at random on the surface of the water with a hissing sound.

The water then turns red litmus paper to blue.

Statement 3

Potassium, K, moves very rapidly at random on the surface of the water. It ignites with a lilac flame with a pop and a hissing sound. The water then turns red litmus paper to blue. Plan a laboratory experiment to investigate the reactivity of lithium, sodium and potassium with water. Your planning should include the following aspects: (a)Aim of the experiment.

(b)All the variables.

(c)Statement of the hypothesis.

(d)List of substance and apparatus.

(e)Procedure of the experiment.

(f)Tabulation of data.

[17 marks]

Kamal Ariffin B Saaim

SMKDBL

http://kemhawk.webs.com/

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