CBSE Class 9 Answered

I want all practical based question in physics and chemistry in class 9.[Please give me those questions from anywhere]

Asked by sajal2402 | 05 Mar, 2018, 11:15: AM

Expert Answer

1. What happens when solutions of sodium sulphate and barium chloride are mixed? Give the reaction.

2. In an experiment, 18.5 g of copper sulphate reacted with 11.0 g of sodium hydroxide to form 10.0 g of copper hydroxide and 19.5 g of sodium sulphate. Which law of chemical combination is illustrated by this data? Give reason for your choice.

3. While verifying the laws of reflection of sound,a student measured the angle between the incident sound wave and reflected sound wave as 100°. What will be the angle of reflection?

4.You are given a mixture of carbon disulphide, benzene, and water. How will the layers form and why? Suggest a method to separate them.

5.A pulse was created in a stretched string of the length of 5 m by four students A, B, C and D. They observed that the pulse returned after reflection at the point of creation 5 times in 10 seconds and calculated the speed as given in the table below:

Student	A	B	C	D
Speed (m/s)	0.5	2.5	5	10

Which student has reported the speed correctly?

6. A gas jar containing air is inverted over a gas jar of bromine vapour. It is observed that after some time, the gas jar containing air also becomes completely reddish brown. Give the reason for this process.

7.There are two nails A and B. Nail A is sharp and nail B is blunt. The area of nail A is
0.1 m2 and that of nail B is 1.5 m2. These nails are to be hammered into a wooden plank. Which nail will be hammered more easily if the force applied is 200 N to hammer both nails? Explain why. Calculate the pressure required to hammer each nail.

8. On which principle is the working of a stethoscope based? State a one-word term for the text ‘hall giving many echoes when sound is incident on its ceiling or wall’.

9.Which of the following will show Tyndall effect?

(a) Salt solution

(b) Milk

(d) Starch solution

10.How will you separate the following:

(i) Oxygen gas from air

(ii) Iron filings from sugar

(iii)Crystals of alum from impure samples

(iv) Common salt from ammonium chloride

Answered by Sivanand Patnaik | 05 Mar, 2018, 12:01: PM