Science (English Medium) Class 11 - CBSE Question Bank Solutions for Chemistry

In an adiabatic process, no transfer of heat takes place between system and surroundings. Choose the correct option for free expansion of an ideal gas under adiabatic condition from the following.

In an exothermic reaction, heat is evolved, and system loses heat to the surrounding. For such system:

(i) q_p will be negative

(ii) ∆_rH will be negative

(iii) q_p will be positive

(iv) ∆_rH will be positive

Heat has randomising influence on a system and temperature is the measure of average chaotic motion of particles in the system. Write the mathematical relation which relates these three parameters.

Increase in enthalpy of the surroundings is equal to decrease in enthalpy of the system. Will the temperature of system and surroundings be the same when they are in thermal equilibrium?

Predict the change in internal energy for an isolated system at constant volume.

Although heat is a path function but heat absorbed by the system under certain specific conditions is independent of path. What are those conditions? Explain.

Match Column (I) with Column (II).

E^Θ values of some redox couples are given below. On the basis of these values.

E^Θ values: \[\ce{Br2 /Br- = + 1.90; Ag+ / Ag(s) = + 0.80}\];

\[\ce{Cu^{2+} / Cu(s) = + 0.34; I2(s) / I- = 0.54}\]

Consider the reactions

(A) \[\ce{H2O2 + 2HI -> I2 + 2H2O}\]

(B) \[\ce{HOCl + H2O2 -> H3O+ + Cl- + O2}\]

Which of the following statements is correct about \[\ce{H2O2}\] with reference to these reactions? Hydrogen perioxide is ______.

Elements of which of the following group(s) of periodic table do not form hydrides.

When the first element of the periodic table is treated with dioxygen, it gives a compound whose solid-state floats on its liquid state. This compound has an ability to act as an acid as well as a base. What products will be formed when this compound undergoes authorisation?

Give reasons why hydrogen resembles alkali metals?

The alkali metals are low melting. Which of the following alkali metal is expected to melt if the room temperature rises to 30°C?

Alkali metals react with water vigorously to form hydroxides and dihydrogen. Which of the following alkali metals reacts with water least vigorously?

The order of decreasing ionisation enthalpy in alkali metals is ______.

Metals form basic hydroxides. Which of the following metal hydroxide is the least basic?

The solubility of metal halides depends on their nature, lattice enthalpy and hydration enthalpy of the individual ions. Amongst fluorides of alkali metals, the lowest solubility of LiF in water is due to ______.

In the synthesis of sodium carbonate, the recovery of ammonia is done by treating NH₄Cl with Ca(OH)₂. The by-product obtained in this process is ______.

By adding gypsum to cement

Which of the following elements does not form hydride by direct heating with dihydrogen?