1

Grade-8

Subject-Chemistry

Kinetic Particle Theory (Revision Class)

A1.1. What correctly describes the molecules in very dilute sugar solution at room temperature?

2. A test-tube containing a liquid X is placed in a beaker of boiling water. The liquid X starts to boil

immediately.

What is the boiling point of liquid X?

A 100 °C

B above 100 °C

C between 0 °C and room temperature

D between room temperature and 100 °C

3. Solid ammonium chloride decomposes on heating according to the following equation.

NH4Cl(s) → NH3(g) + HCl(g)

Which change occurs to the damp red litmus paper in the experiment above?

A remains red

B turns blue and is then bleached

C turns blue and remains blue

D turns blue and then turns red

2

4. The experiment is set up as shown and left until there is no further change.

What is observed?

A a colourless layer below a purple layer

B a colourless liquid with the purple crystal unchanged

C a purple layer below a colourless layer

D a uniformly purple solution

5. A sample of a pure compound is heated until it is completely molten and the compound is then

allowed to cool until it is completely solid again.

The graph shows how the temperature of the compound changes with time.

When are liquid and solid both present?

A P to Q and R to S

B P to Q

C Q to R

D R to S

3 A2 The table shows some information about three gases.

(a) Complete the table by filling in the boxes. [3]

A student heated some solid ammonium chloride, NH4Cl, in a test-tube.

Ammonia and one other gas were formed.

He tested the gases coming out of the tube with litmus paper.

The red litmus quickly turned blue.

A few seconds later, both pieces of litmus paper turned red

(b) Name the process which causes the gases to move along the tube.

......................................................................................................................................[1]

(c) Which gas turned the red litmus paper blue?

......................................................................................................................................[1]

(d) Which gas turned the litmus paper red?

......................................................................................................................................[1]

(e) Explain why the two gases travelled along the test-tube at different speeds.

Use information from the table.

..........................................................................................................................................

..........................................................................................................................................

......................................................................................................................................[2]

Answer sheet of Kinetic ParticTheory:

A1 MCQ

1. A

2. D

3. D

4. D

5. C

A2.

a)

NH3

Hydrogen Chloride 36.5

b) Diffusion

c) Ammonia

d) Hydrogen Chloride

e) The rate of diffusion depends on the mass of the gas particles.NH3 gas travels faster than HCl gas as

NH3 has lower Mr 17 than Mr of HCl 36.5 or vice-versa.

Physics Grade 8 Work Sheet - 3 Topic- Revision Name……………………………………… Sec- …. Date……..

3.

CIDER International School

Grade: VIII Subject: Business Studies

Worksheet- 4 Total Marks: 20

Name:……………………………………………..Sec…….Date……………

SNP manufactures electrical appliances such as cookers and beaters. Parvez’s responsibilities

as Marketing Manager at SNP is to communicate with thousands of customers in many

countries. Some of these customers are wholesalers but many are individual customers who

have bought products directly from the business. Parvez is worried that communication barriers

sometimes prevent his messages being received effectively.

a) What is meant by communication barriers? [4]

b) What is meant by internal and external communications? [4]

c) Identify and explain two types of written communications methods. [6]

d) Identify and explain two causes of communication barriers that SNP may face. [6]

CLASS:VIII [section A & B]

SUBJECT: MATHEMATICS SYLLABUS D /4024

Topic: Transformation (Rotation)