Science (English Medium) कक्षा १२ - CBSE Question Bank Solutions for Chemistry

Match the classes of drugs given in Column I with their action given in Column II.

Assertion: Sulpha drug contain sulphonamide group.

Reason: Salvarsan is a sulpha drug.

In what respect do prontosil and salvarsan resemble. Is there any resemblance between azo dye and prontsil? Explain.

Arrange the following in the increasing order of their property indicated:

ethanol, ethanoic acid, benzoic acid (boiling point)

Account for the following:

Acylation of aniline is carried out in the presence of pyridine.

Arrhenius equation can be represented graphically as follows:

The (i) intercept and (ii) slope of the graph are:

Explain how and why will the rate of reaction for a given reaction be affected when the temperature at which the reaction was taking place is decreased.

Give reasons for the following observation:

pK_b of aniline is lower than the m-nitroaniline.

Account for the following:

Arrange the following compounds in the increasing order of their basic strength in aqueous solution: CH₃NH₂,(CH₃)₃N,(CH₃)₂NH

Write the main product in the following reaction:

\[\ce{2CH3COCl + (CH3)2Cd ->}\]

Arrange the following compounds in increasing order of their boiling points:

CH₃CH₂OH, CH₃−CHO, CH₃−COOH

A first-order reaction is 50% complete in 30 minutes at 300 K and in 10 minutes at 320 K. Calculate activation energy (E_a) for the reaction. [R = 8.314 J K⁻¹ mol⁻¹]

[Given: log 2 = 0.3010, log 3 = 0.4771, log 4 = 0.6021]

Calculate the Δ_rG⁰ and log K_c, for the given reaction at 298 K:

\[\ce{Ni_{(s)} + 2Ag^+_{( aq)} <=> Ni^{2+}_{( aq)} + 2Ag_{(s)}}\]

Given: `"E"_("Ni"^(2+)//"Ni")^0` = −0.25 V, `"E"_("Ag"^+//"Ag")^0` = +0.80 V, 1F = 96500 C mol⁻¹.

Among the following, which has the highest value of pK_b?

What happens to the rate constant k and activation energy E_a as the temperature of a chemical reaction is increased? Justify.

Why is the boiling point of o-dichlorobenzene higher than p-dichlorobenzene, but the melting point of para-isomer is higher than ortho-isomer?

Arrange the following in order of increasing boiling point:

Ethoxyethane, Butanal, Butanol, n-butane

Hydrolysis of sucrose is called ______.

Assertion (A): Alcohols react both as nucleophiles and electrophiles.

Reason (R): The bond between C–O is broken when alcohols react as nucleophiles.

Select the most appropriate answer from the options given below:

Arrange the isomeric dichlorobenzene in the increasing order of their boiling point and melting points.