2018_Combined science_olevel_nov_paper3

Extracted Content: 2018_Combined science_olevel_nov_paper3

Page 1

Extracted Text

In bites: Seer

ZIMBABWE SCHOOL EXAMINATIONS COUNCIL

General Certificate of Education Ordinary Level

COMBINED SCIENCE 4003/3

PAPER 3 (Practical Test)

NOVEMBER 2018 SESSION | hour 30 minutes

Candidates answer on the question paper
Additional materials:

As listed in instructions to Supervisors
Calculator (optional)

INSTRUCTIONS TO CANDIDATES
Write your name, centre number and candidate number in the spaces at the top of this page.

Answer both questions.
Write your answers in the spaces provided on the question paper.
Use a sharp pencil for your drawings. Coloured pencils or crayons should not be used.

You should record all experimental results and show the essential steps in any calculation in
the spaces provided in the question paper.

FOR EXAMINER’S USE

INFORMATION FOR CANDIDATES

ji
The number of marks is given in brackets [ ] at the end of Sr
each question or part question. TOTAL a

Copyright: Zimbabwe School Examinations Council, N2018.
© ZIMSEC 2018

---

Page 2

Extracted Text

Answer all questions.

You are required to determine the pH of three liquids, Al, A2 and A3.
You are provided with the three liquids in test tubes labelled Al, A2 and A3, universal indicator
solution, a universal indicator chart and a dropper.

(a) (i) Add 2 drops of universal indicator solution to each of the liquids Al, A2 and
A3. Record the colour and pH of each of the liquids in Table 1.1.

Table 1.1

colour after adding acid-base nature of
universal indicator liquid
solution

(b)

(ii) State the colour of the universal indicator solution,

ib i i aeata {1}
Apart from using universal indicator solution or universal indicator paper, describe
another way of determining the acid-base nature of liquids Al, A2 and A3, stating the
expected results for each of the liquids.

15]

40043 N2018

---

Page 3

Extracted Text

(fc) =i) State any one precaution that should be taken during the experiment.

(ii) State one possible source of error in the experiment.

40033 N20

---

Page 4

Extracted Text

2. You are required to compare the densities of water and cooking oil, You are provided with water and cooking oil, 2 beakers labelled A and B, a measuring cylinder and access to a balance.

Measure the mass of the empty beaker labelled A and record the mass in Table 2.1
under the column labelled for water.

Measure 20,0 cm? of water and pour it into beaker A.
Record the mass of the water and the beaker in the table of results.
Calculate the mass of the water and record it in the table of results. Repeat the procedure
using beaker B and cooking oil instead of water.
Table 2.1

for cooking oil

ear Me
cic

(b) (i) Calculate the density of the water.

(ii) Calculate the density of the cooking oil.

(ec) Mix about 5 cm? of water and about 5 em? of cooking oil in a test tube.
State, giving a reason, the liquid that oats.

@ State one source of error in the experiment.

(ii) Suggest one way of improving the experiment.

40033 N2018

---