#### Acids, Bases and Salts Book Back Questions

9th Standard

Reg.No. :
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Science

Time : 00:45:00 Hrs
Total Marks : 30
6 x 1 = 6
1. Zn + 2HCI $\longrightarrow$ ZnCl2 + ____$​​​​\uparrow$(H2' 02' CO2)

(a)

H2

(b)

02

(c)

CO2

(d)

CO2

2. Apple contains malic acid. Orange contains_______

(a)

citric acid,

(b)

ascorbic acid

(c)

citric acid,

(d)

acid

3. pH value of human blood is_________

(a)

7.0

(b)

7.4

(c)

7.6

(d)

7.6

4. The nature of the tooth paste commonly used is in nature

(a)

acidic

(b)

basic

(c)

neutral

(d)

neutral

5. You are given pure water to test the pH value using pH paper. It shows colour

(a)

White

(b)

black

(c)

green

(d)

black

6. The hydrated salt of copper sulphate has______colour

(a)

Red

(b)

White

(c)

Blue

(d)

White

7. 3 x 3 = 9
8. Give the significance of pH of soil in agriculture.

9. When does the acid rain occur?

10. What are the uses of Plaster of Paris?

11. 3 x 5 = 15
12. Why does distilled water not conduct electricity whereas rain water does?

13. Plaster of Paris should be stored in a moisture proof container. why?

14. Sulphuric acid is called King of Chemicals. Why is it called so?