English Medium इयत्ता १० - CBSE Important Questions

Write the method of preparation of Ca(OH)₂. What happens when CO₂ is passed through it? Write balanced chemical equation for the reaction involved.

You are asked to prepare hard water in your laboratory. Select a group from the following groups of salts, any salt of which you may dissolve in distilled water to obtain hard water.
(A) NaCl; Na2SO4; KCl
(B) NaCl; CaCl2; KCl
(C) CaCl2; CaSO4; MgSO4
(D) Na2SO4; CaSO4; MgSO4

Out of HCl and CH₃COOH, which one is a weak acid and why? Describe an activity to support your answer.

Out of three metals P, Q and R, P is less reactive than Q and R is more reactive than P and Q both. Suggest an activity to arragne P, Q and R in order of their decreasing reactivity. 

Answer the following question.
Identify the acid and the base from which sodium chloride is obtained. Which type of salt is it? When is it called rock salt? How is rock salt formed?

A compound which is prepared from gypsum has the property of hardening when mixed with water. identify the compound and write its formula. How is this compound prepared? Describe it in the form of a chemical equation only.

One of the events that does not occur during photosynthesis is ______.

A small amount of copper oxide was taken in a beaker and dilute hydrochloric acid was added with continuous stirring of the solution. Name the compound formed and state the colour of its solution. Write the balanced chemical equation for the reaction that occurs. Based on the reaction, state the nature (acidic/basic) of copper oxide.

An aqueous solution of a salt turns blue litmus to red. The salt could be the one obtained by the reaction of ______.

Define the following:

Reflex arc

Nervous and hormonal systems together perform the function of control and coordination in human beings. Justify this statement with the help of an example.

Name the parts (a) to (e) in the following diagram.

What is the term given to the sequence of events occurring in the diagram?

Plants do not have any nervous system but yet, if we touch a sensitive plant, some observable changes take place in its leaves. Explain how could this plant respond to the external stimuli and how it is communicated.

How is an electric impulse created in human nervous system? 

A plant growth inhibitor hormone which causes wilting of leaves is ______.

Trace the sequence of events which occur when you suddenly touch a hot object.

Name the parts labelled as A, B, C and D in the diagram given below:-

(i) Name the part marked 'A' in the diagram.

(ii) How dose 'A' reachese part 'B'?

(iii) State the importance of the part 'C'.

(iv) What happens to the part marked 'D' after fertilisation is over?

A student while observing an embryo of a pea seed in the laboratory listed various parts of the embryo as given below:

Testa, Tegmen, Radicle, Plumule, Micropyle, Cotyledon.

On examining the list the teacher remarked that only three parts are correct. Select three correct parts from the above list:

(a) Testa, Radicle, Cotyleddon

(b) Tegmen, Radicle, Micropyle

(c) Cotyledon, Plumule, Testa

(d) Radicle, Cotyledon, Plumule

"The chromosomal number of the sexually producing parents and their offspring is the same." Justify this statement.