Physical Chemistry

The $\text{Cu}$ metal crystallises into fcc lattice with a unit cell edge length of $361\text{ pm}$. The radius of $\text{Cu}$ atom is:

Arrange the following in decreasing order of number of molecules contained in:

Camphor in nitrogen gas is a type of solution:

A molecule $\text{X}$ associates in a given solvent as per the following equation: $$n\text{X} \rightleftharpoons (\text{X})_n$$ For a given concentration of $\text{X}$, the van 't Hoff factor was found to be $0.80$ and the fraction of associated molecules was $0.3$. The correct value of '$n$' is:

Consider the following statements regarding osmotic pressure:

Read the following passage and answer questions 32 to 36: Battery or cell converts chemical energy of the redox reaction to electrical energy. In fuel cell (a galvanic cell), the chemical energy of combustion of fuels like $\text{H}_2$, ethanol, etc. are directly converted to electrical energy. In a fuel cell, $\text{H}_2$ and $\text{O}_2$ react to produce electricity, where $\text{H}_2$ gas is oxidised at anode and oxygen is reduced at cathode and the reactions involved are: $$\text{Anode reaction}: \text{H}_2 + 2\text{OH}^- \rightarrow 2\text{H}_2\text{O} + 2\text{e}^- \quad | \quad \text{Cathode reaction}: \text{O}_2 + 2\text{H}_2\text{O} + 4\text{e}^- \rightarrow 4\text{OH}^-$$ $67.2\text{ L}$ of $\text{H}_2$ at STP reacts in $15\text{ minutes}$.

The number of moles of hydrogen oxidised is:

(Based on Fuel Cell Passage) The number of moles of electrons produced in the oxidation of $67.2\text{ L}$ of $\text{H}_2$ at STP is:

(Based on Fuel Cell Passage) The quantity of electricity produced in the oxidation of $67.2\text{ L}$ of $\text{H}_2$ at STP is:

(Based on Fuel Cell Passage) If the entire current produced is used for the electrodeposition of Silver (at. wt. $108\text{ g mol}^{-1}$) from Silver (I) solution, the amount of silver deposited will be:

(Based on Fuel Cell Passage) The source of electrical energy on the Apollo moon flight was:

For the following reaction: $$2\text{A}_2 (g) + \frac{1}{4} \text{X} (g) \rightarrow 2\text{A}_2\text{X} (g)$$ Volume is increased to double its value by decreasing the pressure on it. If the reaction is first order with respect to $\text{X}$ and second order with respect to $\text{A}_2$, the rate of reaction will:

Identify the order of reaction if its rate constant is $k = 2 \times 10^{-2}\text{ s}^{-1}$:

For a complex reaction, the order of reaction is equal to:

If $75\%$ of a first order reaction gets completed in $32\text{ minutes}$, time taken for $50\%$ completion of this reaction is:

The gold number range of some of the lyophilic colloids is given below: $$\text{A}: 0.005 - 0.01, \quad \text{B}: 0.15 - 0.25, \quad \text{C}: 0.04 - 1.0, \quad \text{D}: 15 - 25$$ Which among these can be used as a better protective colloid?