CBSE Important Questions

Science (Chemical Reaction)

1. The Ph of a neutral solution is

1. 7
2. Greater than 7
3. Less than 7
4. Zero

2. The color of methyl orange in acidic solution is

1. red
2. yellow
3. orange
4. green

3. When phenolphthalein is put in acidic solution we observed the following color

1. red
2. blue
3. colorless
4. pink

4. The Ph of distilled water is

1. greater then 7
2. less than 7
3. 7
4. None

5. When a moist paper Ph is introduced in a test tube containing acetic acid, the colour changes into

1. red
2. orange
3. blue
4. green

6. Colures shown at the extreme ends of Ph scale are

1. red & blue
2. red & green
3. red and yellow
4. blue and green

7. As we increase the basicity of some compound we actually increase its

1. RH
2. pOH
3. pH
4. none

8. Which type of clothes is not desirable in laboratory?

1. Cotton
2. Wool
3. synthetic
4. All of above

9. The percentage of ethanoic acid in vinegar is

1. 20
2. 15
3. 10
4. 5

10. The ore of mercury is

1. Cinnabar
2. Cryolite
3. Bauxite
4. Magnetite

11. The gas evolved when sodium carbonate reacts with HCl

1. Hydrogen
2. Oxygen
3. Nitrogen
4. Carbon di- oxide

12. When zinc reacts with HCl the gas evolved is

1. Hydrogen
2. Oxygen
3. Nitrogen
4. Carbon di- oxide

13. A base which is alkali

1. NaOH
2. Fe(OH)3
3. Cu(OH)3
4. Al(OH)3

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• Science (Important Question)
• Chemical Reactions (Important Question)