Candidates Name: …………………………………………………………………………………………. Centre/Index No: …………/………………..

School: ……………………………………………………………………………………………………………. Signature: ………………………………………

545/1
CHEMISTRY
Paper 1
June/July 2025
PRE-MOCK
2 hours

EXCEL ASSESSMENT HUB, WAKISO.

Uganda Certificate of Education.
Chemistry

Paper 1

2 hours

INSTRUCTIONS TO CANDIDATES:

This paper consists of two sections: A and B.

Section A has two compulsory items.

Section B has two Parts; I and II. Answer one item from each part.

Answer four items in all.

Answers to Section A must be written in the spaces provided while those of section B
must be written on the answer sheets provided.

Any additional item(s) answered will not be marked

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 SECTION A

Answer both items from this section in the spaces provided.

Item 1.
A group of S.4 students were having a discussion during a chemistry lesson about the
changes that occur in our daily lives. One student brought up common examples such
as freezing water to form ice, frying an egg, boiling water, rotting and decaying food.
However, another student raised a concern, pointing out that these changes are not all
the same especially in terms of what is produced or left behind after each change
happens. This caused some confusion among the group, as they were unsure what
exactly made the changes different or similar.

Task:
As a learner of chemistry in Senior Four:

(a) Help the group of students classify the changes mentioned into appropriate types
of changes based on their characteristics.

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(b) Choose one category of change from (a) and describe its key properties that help
distinguish it from other types.

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(c) Pick any one of the examples mentioned in the discussion and explain how that
type of change can affect the environment.

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©Excel Assessment Hub 2025 CHEMISTRY
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ITEM 2.
Mr. John, a well-known local cook, was having a lively conversation with one of his friends about
the curry powder he uses to make his food taste better. He mentioned that he often uses brands
like Chico and Royco, and explained that these contain food additives that enhance the flavour
and appearance of his meals. However, his friend was a bit confused. He believed that curry
powder itself is just a food additive, and didn’t understand how it could contain other additives.
Mr. John had to take time to explain the difference clearly.

Task:
As a learner of chemistry:
(a) Help Mr. John identify any category or categories of food additives that are commonly
found in curry powder.
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(b) Explain how these additives work to make food more appealing and delicious.
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©Excel Assessment Hub 2025 CHEMISTRY

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(c) Mention some potential side effects associated with the use of such additives, and
describe how these effects can be prevented or reduced.
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SECTION B

Part I

Answer one item from this part

Item 3.

In one of the rural villages in Uganda, residents have long struggled with limited access
to essential household products such as soap. Retailers in the area are forced to travel
long distances to purchase detergents, which increases transport costs and raises the
final price of soap for local consumers. Recently, a private investor has proposed to set
up a small-scale soap manufacturing plant within the village. This news has been
warmly received by the residents, as it promises to improve access and affordability.
However, many community members are uncertain about the chemical processes
involved in soap production and are concerned about possible effects on their health
and the environment.

In light of these concerns, the local council has organized a community meeting to help
residents understand the nature of soap manufacturing. You have been invited to speak
at this meeting to help clarify these issues and address the residents’ questions.

Task:

As a chemistry student, prepare a message you will deliver to the residents during the
meeting.
©Excel Assessment Hub 2025 CHEMISTRY
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Item 4
Iron is an essential raw material used in the manufacture of tools, construction equipment, and
infrastructure such as bridges and roads. With Uganda’s growing population and the ongoing
push for industrialization, a private investor has identified iron ore deposits in a rural district in
eastern Uganda and plans to establish an iron smelting plant in the area.
While some local leaders welcome the project for its potential to stimulate development, many
residents have expressed concern about its possible effects on their health, environment, and
farmland. As a result, they have approached their LC1 chairman, demanding a clear explanation
before the project proceeds.
In response, the chairman agrees that the community must first be sensitized about what the
industry involves. He has requested that residents be educated on how iron is processed, what
benefits the factory could bring, what negative side effects may occur, and what steps can be
taken to manage or prevent these problems.
Task:
As a student of chemistry, prepare a write-up that the LC1 chairman can use to educate his
community.

Part II
Answer one item from this part.
Item 5
In one of the districts in Uganda, rocks and minerals are increasingly being extracted from the
land through activities like quarrying and open-pit mining. These activities have grown rapidly,
often taking place without clear guidelines or proper regulation. This has raised concern among
local residents, especially as they begin to observe changes in their surroundings and
livelihood.
A group of elders and youth leaders from the area have approached their Member of Parliament
(MP), voicing concerns about how rocks and minerals are being handled in their community.
They worry that the activities may not be sustainable and may be causing more harm than
good. The MP has agreed that it is important for the community to understand the value of these
resources, how they are being used, and the possible impact of misusing them.

In response, the MP has organized a public dialogue to raise awareness among the
residents. You have been invited to contribute to this dialogue based on your knowledge
of chemistry and natural resources.

Task:

As a learner of chemistry, prepare a message you will deliver to the residents during the
meeting.

©Excel Assessment Hub 2025 CHEMISTRY

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Item 6.

In a rapidly growing town in Uganda’s central region, the increase in vehicles, small
factories, and open burning of waste has led to noticeable changes in the quality of the
air residents breathe. Many people, especially children and elderly, have started
experiencing respiratory problems. Concerned by these health issues, the community
members approached their local council chairperson to raise their worries. The
chairperson acknowledges the problem but believes that many residents may not fully
understand what causes poor air quality or how it affects their health and environment.

To address this, the chairperson has organized a community meeting and invited you, a
chemistry student, to educate the people on the importance of clean air and ways the
community can protect and improve the air they depend on.

Task:

Prepare a message to deliver at the meeting.

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