Applications of physical and chemical changes Practice exercise 8

A farmer burns a pile of dry leaves. Smoke rises, and ash remains as shown below. What type of change is taking place during the burning of the leaves?  (1 mark)

A farmer burns a pile of dry leaves. Smoke rises, and ash remains as shown below. What type of change is taking place during the burning of the leaves?  (1 mark)

A farmer burns a pile of dry leaves. Smoke rises, and ash remains as shown below. What type of change is taking place during the burning of the leaves?  (1 mark)

A farmer burns a pile of dry leaves. Smoke rises, and ash remains as shown below. What type of change is taking place during the burning of the leaves?  (1 mark)

A spoon was left in salty soup overnight. By morning, brown patches had formed. What type of change happened and how can it be prevented?  (1 mark)

A spoon was left in salty soup overnight. By morning, brown patches had formed. What type of change happened and how can it be prevented?  (1 mark)

A spoon was left in salty soup overnight. By morning, brown patches had formed. What type of change happened and how can it be prevented?  (1 mark)

A spoon was left in salty soup overnight. By morning, brown patches had formed. What type of change happened and how can it be prevented?  (1 mark)

Some villagers burn plastic waste. Others complain of smoke and smell. What type of change happens when plastic burns, and what is one benefit and one danger? (1 mark)

Some villagers burn plastic waste. Others complain of smoke and smell. What type of change happens when plastic burns, and what is one benefit and one danger? (1 mark)

Some villagers burn plastic waste. Others complain of smoke and smell. What type of change happens when plastic burns, and what is one benefit and one danger? (1 mark)

Some villagers burn plastic waste. Others complain of smoke and smell. What type of change happens when plastic burns, and what is one benefit and one danger? (1 mark)

Some villagers burn plastic waste. Others complain of smoke and smell. What type of change happens when plastic burns, and what is one benefit and one danger? (1 mark)

The diagram below shows a freezer with fish placed inside. Ice crystals are forming around the fish. What kind of change is taking place in the fish during freezing?  (1 mark)

The diagram below shows a freezer with fish placed inside. Ice crystals are forming around the fish. What kind of change is taking place in the fish during freezing?  (1 mark)

The diagram below shows a freezer with fish placed inside. Ice crystals are forming around the fish. What kind of change is taking place in the fish during freezing?  (1 mark)

The diagram below shows a freezer with fish placed inside. Ice crystals are forming around the fish. What kind of change is taking place in the fish during freezing?  (1 mark)

The diagram below shows a freezer with fish placed inside. Ice crystals are forming around the fish. What kind of change is taking place in the fish during freezing?  (1 mark)

Two groups performed experiments. One boiled water to kill germs. The other burned firewood to heat the water. Which statement best explains the type of change in each process?  (1 mark)

Two groups performed experiments. One boiled water to kill germs. The other burned firewood to heat the water. Which statement best explains the type of change in each process?  (1 mark)

Two groups performed experiments. One boiled water to kill germs. The other burned firewood to heat the water. Which statement best explains the type of change in each process?  (1 mark)

Two groups performed experiments. One boiled water to kill germs. The other burned firewood to heat the water. Which statement best explains the type of change in each process?  (1 mark)

Look at the image of a glass of juice with ice cubes. Why does the drink become cooler after adding ice?

David poured warm mango juice into a glass and added a few ice cubes. After a few minutes, he noticed the juice felt colder. Based on your understanding of change of state, why did this happen?    (1mark)

David poured warm mango juice into a glass and added a few ice cubes. After a few minutes, he noticed the juice felt colder. Based on your understanding of change of state, why did this happen?    (1mark)

David poured warm mango juice into a glass and added a few ice cubes. After a few minutes, he noticed the juice felt colder. Based on your understanding of change of state, why did this happen?    (1mark)

David poured warm mango juice into a glass and added a few ice cubes. After a few minutes, he noticed the juice felt colder. Based on your understanding of change of state, why did this happen?    (1mark)

David poured warm mango juice into a glass and added a few ice cubes. After a few minutes, he noticed the juice felt colder. Based on your understanding of change of state, why did this happen?    (1mark)

David poured warm mango juice into a glass and added a few ice cubes. After a few minutes, he noticed the juice felt colder. Based on your understanding of change of state, why did this happen?    (1mark)

During transportation, vegetables are packed in refrigerated trucks. Why is this important in terms of change of state?

Vegetable suppliers from Mwea use refrigerated trucks to transport fresh produce to Nairobi. During hot seasons, vegetables spoil quickly when not refrigerated. Based on your understanding of change of state, why is refrigeration necessary during transport?    (1mark)

Vegetable suppliers from Mwea use refrigerated trucks to transport fresh produce to Nairobi. During hot seasons, vegetables spoil quickly when not refrigerated. Based on your understanding of change of state, why is refrigeration necessary during transport?    (1mark)

Vegetable suppliers from Mwea use refrigerated trucks to transport fresh produce to Nairobi. During hot seasons, vegetables spoil quickly when not refrigerated. Based on your understanding of change of state, why is refrigeration necessary during transport?    (1mark)

Vegetable suppliers from Mwea use refrigerated trucks to transport fresh produce to Nairobi. During hot seasons, vegetables spoil quickly when not refrigerated. Based on your understanding of change of state, why is refrigeration necessary during transport?    (1mark)

Why is steaming preferred when cooking dumplings in a hotel kitchen in Nairobi?

A chef in a Nairobi hotel prefers steaming dumplings instead of frying them. He places them above boiling water in a covered sufuria. Based on your understanding of change of state, why is steaming preferred in this situation?   (1mark)

A chef in a Nairobi hotel prefers steaming dumplings instead of frying them. He places them above boiling water in a covered sufuria. Based on your understanding of change of state, why is steaming preferred in this situation?   (1mark)

A chef in a Nairobi hotel prefers steaming dumplings instead of frying them. He places them above boiling water in a covered sufuria. Based on your understanding of change of state, why is steaming preferred in this situation?   (1mark)

A chef in a Nairobi hotel prefers steaming dumplings instead of frying them. He places them above boiling water in a covered sufuria. Based on your understanding of change of state, why is steaming preferred in this situation?   (1mark)

Observe the image. What change of state occurs when water boils on a jiko as shown below?

A cook is preparing ugali in a sufuria and notices steam rising as water heats beneath the maize flour as illustrated below. Based on your understanding of change of state, what process explains the formation of this steam?   (1mark)

A cook is preparing ugali in a sufuria and notices steam rising as water heats beneath the maize flour as illustrated below. Based on your understanding of change of state, what process explains the formation of this steam?   (1mark)

A cook is preparing ugali in a sufuria and notices steam rising as water heats beneath the maize flour as illustrated below. Based on your understanding of change of state, what process explains the formation of this steam?   (1mark)

A cook is preparing ugali in a sufuria and notices steam rising as water heats beneath the maize flour as illustrated below. Based on your understanding of change of state, what process explains the formation of this steam?   (1mark)

A cook is preparing ugali in a sufuria and notices steam rising as water heats beneath the maize flour as illustrated below. Based on your understanding of change of state, what process explains the formation of this steam?   (1mark)

A cook is preparing ugali in a sufuria and notices steam rising as water heats beneath the maize flour as illustrated below. Based on your understanding of change of state, what process explains the formation of this steam?   (1mark)

Farmers in Eldoret place freshly milked milk cans in a basin filled with ice blocks. Why does this help preserve the milk?

After milking in the morning, farmers in Eldoret place milk cans in a basin filled with ice blocks, as shown below, before transporting the milk to the collection center. Based on your understanding of change of state, why is this method effective for preservation?  (1 mark)

After milking in the morning, farmers in Eldoret place milk cans in a basin filled with ice blocks, as shown below, before transporting the milk to the collection center. Based on your understanding of change of state, why is this method effective for preservation?  (1 mark)

After milking in the morning, farmers in Eldoret place milk cans in a basin filled with ice blocks, as shown below, before transporting the milk to the collection center. Based on your understanding of change of state, why is this method effective for preservation?  (1 mark)

After milking in the morning, farmers in Eldoret place milk cans in a basin filled with ice blocks, as shown below, before transporting the milk to the collection center. Based on your understanding of change of state, why is this method effective for preservation?  (1 mark)