English Medium कक्षा १० - CBSE Important Questions

List two differences between the properties exhibited by covalent compounds and ionic compounds.

Assertion (A): Melting point and boiling point of ethanol are lower than that of sodium chloride.

Reason (R): The forces of attraction between the molecules of ionic compounds are very strong.

Name the compound formed when ethanol is heated at 443 K in the presence of conc. \[\ce{H2SO4}\] and draw its electron dot structure.

State the role of conc. \[\ce{H2SO4}\] in the reaction.

The electron dot structure of chlorine molecule is:

Why is glacial acetic acid called so?

What happens when ethanol is heated at 443K in the presence of conc. H₂SO₄? Write the role of conc. H₂SO₄ in this case.

Write an equation showing saponification.

Write the chemical equation for the following:

Esterification Reaction

Which of the following endocrine gland does not occur as a pair in the human body?

A student was asked to observe and identify the various parts of an embryo of a red kidney bean seed. He identified the parts and listed them as under:

I. Tegmen

II. Testa

III. Cotyledon

IV. Radicle

V. Plumule

The correctly identified parts among these are

(A) I, II and III

(B) II, III and IV

(C) III, IV and V

(D) I, III, IV and V

In the following diagram showing the structure of embryo of a dicot seed, what are the parts marked I, II and III sequentially?

A student has to perform the experiment "To identify the different parts of an embryo of a dicot seed." Select from the following an appropriate group of seeds:

(a) Pea, gram, wheat

(b) Red kidney bean, maize, gram

(c) Maize, wheat, red kidney bean

(d) Red kidney bean, pea, gram

Name and differentiate between the two modes of pollination in flowering plants.

A student identified the various parts of an embryo of a gram seed and listed them as given below :

(I) Testa

(II) Plumule

(III) Radicle

(IV) Cotyledon

(V) Tegmen

Out of these the actual parts of the embryo are :

(A) I, II, III

(B) II, III, IV

(C) III, IV, V

(D) II, IV, V

You are asked by your teacher to study the different parts of an embryo of a gram seed. Given below are the steps to be followed for the experiment:

I. Soak the gram seeds in plain water and keep them overnight.

II. Cut open a soaked seed and observe its different parts.

III. Take some dry gram seeds in a petri dish.

IV. Drain the excess water.

V. Cover the soaked seeds with a wet cotton cloth and leave them for a day.

The correct sequence of these steps is :

(A) III, I, V, IV, II

(B) III, I, II, IV, V

(C) III, IV, V, I, II

(D) III, I, IV, V, II

(a) Identify A, B and C in the given diagram and write their functions.

(b) Mention the role of gamete and zygote in sexually reproducing organisms.

In the figure, the parts marked A, B and C are sequentially:

(A) Plumule, Radicle and Cotyledon

(B) Radicle, Plumule and Cotyledon

(C) Plumule, Cotyledon and Radicle

(D) Radicle, Cotyledon and Plumule

List any two differences between pollination and fertilization.

Answer the following question.
How does suitable pollination lead to fertilization?

A student is observing the temporary mount of a leaf peel under a microscope. Draw a labelled diagram of the structure of stomata as seen under the microscope