Revision work for chemistry Grade-8 2021.

Revision work for chemistry Grade-8 2021. 

Chose the best.

1.    In a brewery the Fermentation is carried out 

       in ------------------- vats.

A.   Small

B.   Large

C.   Medium

D.   All

2.    Drugs are substances which affect 

       the ----------------------- in some way.

A.   Plastic

B.   Rocks

C.   Body

D.   None of them

3.    In the 1950s a new drug called Paracetamol was           introduced.

A.   Paracetamol

B.   Placebo

C.   Emulsion

D.   Fermentation

4.    An Emulsion is an example of a ----------------.

A.   Emulsion

B.   Fermentation

C.   Placebo

D.   Colloidal

5.    Detergents are ------------------ agents.

A.      Soft

B.      Cleaning

C.      Bad

D.      All

True and False

1.    The industries tend to run their processes continuously. T

2.    Aspirin is used for headaches, fevers, and in larger doses for arthritis. T

3.    A French chemist called Charles Frederic Gerhardt made a safer drug in 1750.F

4.    The pigments are soluble in acrylic. T

5.    We can also use the Aspirin to test fuses or batteries. F

 Fill in the blanks.

1.    The industries tend to run their processes ------------------- . continuously

2.    These continuous processes are ----------------------- . economical

3.    In a brewery the ------------------------- is carried out in large vats. Fermentation

4.    A ---------------------------------- is not as efficient as a continuous process in       general. batch process

5.    They can automatically mix all possible combinations of promising reactants.   This is called ------------------------- chemistry. Combinatorial

6.    The clinical trials will involve the use of a -------------------- test group. Placebo

7.   ------------------- are substances which affect the body in some way. Drugs

8.    The development of a class of drugs called ----------------------- . These are   drugs that relieve pain. Analgesics

9.    The Egyptians used a bush called ----------------- to make a treatment for   muscle pains. Myrtle

10. In 1835 another plant, a flower from the ----------------------, was also   discovered to have these analgesic effects. riverbank

11. A French chemist called Charles Frederic Gerhardt made a safer drug               in----------------------------. 1853

12. ------------------ is used for headaches, fevers, and in larger doses for arthritis. Aspirin

13. in the 1950s a new drug called --------------------- was introduced. Paracetamol

14. A ------------------------- to help the paint attach itself to an object and to form a   protective film when dry. Binder

15. An ------------------------ is an example of a colloid. Emulsion

16. A ------------------------- is a finely dispersed mixture of two or more substances that do not dissolve in each other. Colloid

17. They are suspended in the paint. They are so tiny that they don't settle out easily. We call this type of colloid a sol or a ------------------- . suspension

18. Some substances respond to temperature changes by changing -------------. colour

19. We can also use the ------------------------------ pigments to test fuses or batteries. Thermochromic

20. The pigments are soluble in ----------------------- . acrylic 

21. -------------------------------------- are cleaning agents. Detergents

22. A ----------------------- the actual detergent that removes the grease. surfactant