Explore topic-wise InterviewSolutions in .

__ is the force which holds two or more atoms together in a stable molecule.

Out of the following which is an artificial ecosystem?

The phenomenon of occurrence of same element in different physical forms is known as ___________.

In the bond between alkali metals and chalcogens, which of the following electronic activity will take place?

Silver ore is related with NaCN (aq) to

A.)reduce metal

B.)extract pure silver

C.)refine silver

D.)to remove the impurities

A dilute solution of sodium carbonate was added to two test tubes – one containing dil $HCl$ (A) and the other containing dilute $NaOH$ (B). What will be observations?

(a) What are acidic and basic flux?

(b) Why does iron or zinc not occur free in nature?

What is the number of moles of hydrogen atom in 72 g of water?

What actually a alcohol is - an acid or a base?

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When a drop of an unknown solution X is placed on a strip of pH paper, a deep blue colour is produced. This sample should be which one of the following?

Give one example of a decomposition reaction which is carried out :

(a) with electricity

(b) by applying heat

Carbon dioxide gas is liberated when $HCl$ acid is added to:

Name 3 chemical reaction in which heat is evolved and 3 chemical reaction in which heat is absorbed

Write the balanced equations for the following reactions, and add the state symbols :

(a) Magnesium carbonate reacts with hydrochloric acid to produce magnesium chloride, carbon dioxide and water.

(b) Sodium hydroxide reacts with sulphuric acid to produce sulphate and water

The inflammation caused by a bee sting can be reduced by using:

When $CuS{O}_4.5H_{2}O$ is heated, the products are:

The oxidizing properties of Nitric Acid are due to

A gas cylinder of capacity of 20 dm³ is filled with gas X the mass of which is 10 g. When the same cylinder is filled with hydrogen gas at the same temperature and pressure the mass of the hydrogen is 2 g, hence the relative molecular mass of the gas is:

(a) Give the molecular formula of one homologue of each of the following :
(i) $C_3{H}_6$ (ii) $C_2{H}_6$ (iii) $C_2{H}_2$
(b) What is the difference in the molecular mass of any two adjacent homologues?
(c) By how many carbon atoms and hydrogen atoms do any two adjacent homologues differ?

In nature, aluminium is found in the form of compounds while gold is found in the free state. Give reason.

The Oxidation state of Mn in $K_{2}Mn{O}_4$ is

Is calcium oxide used for whitewashing or calcium hydroxide? Write in brief.

What will happen if we give light(decompostion)reaction to Ag2S(silversulphide)

What happens when HCl is in the gaseous state?

Will the dilution of acid leads to decrease in ph value

Do all metals react with bases to give H2 or all metals react to give H2?

Few drops of universal indicator are added to three colourless solutions taken separately in three test tubes labeled as P, Q, R respectively. The colour change of the solutions are marked in the following figures:

Arrange the test tubes in a descending order as per the pH value?

Calculate the percentage of nitrogen and oxygen in ammonium nitrate.

[Relative molecular mass of ammonium nitrate is 80, H = 1, N= 14, 0= 16],

(a) Name an element which reacts with hydrogen to form a compound which is strongly acidic in water.
(b) Explain why dilute hydrochloric acid cannot be concentrated by boiling beyond 22.2%.

A compound has the following percentage composition by mass-

Carbon-14.4%

Hydrogen-1.2%

Chlorine-85.5%

The relative molecular mass of this compound is 168.50 what ia is molecular formula?

Identify the component oxidised in the following reaction :

$H_{2}S+C{I}_2⟶S+2HCI$

Define Gay Lusaac’s law of combining volumes of gases. Explain it with an example.

Which of the following is an alloy of mercury with silver and tin as a metal?

$CaO\left(s\right)+H_{2}O\left(l\right)\to Ca\left(OH{)}_2\right(aq)+heat$

What can be inferred from the above reaction?

(i) $CaO$ is solid.

(ii) $CaO$ reacts with water.

(iii) $H_{2}O$ is liquid.

(iv) $H_{2}O$ is in vapour state.

(v) $Ca(OH{)}_2$ forms a solution with water.

(vi) The reaction is exothermic.

The electrovalent compounds are formed by the transfer of electrons from:

Choose the correct option regarding the balanced reaction of alcohol with sodium.

The atomic number of an element Y is 16.
(a) What must an atom of Y do to achieve the nearest inert gas electron arrangement?
(b) Which inert gas is nearest to Y?

In each of the following pairs, choose the atom having the bigger size :

(a) Mg (At. No. 12) or Cl (At. No. 17)

(b) Na (At. No. 11) or K (At. No. 19)

An electron and a proton are separated by a large distance and the electron approaches the proton with K.E. of 2 eV. If the electron is captured by the proton to form a hydrogen atom in the ground state, wavelength of photon emitted will be