Schottky defect in crystals is observed when equal number of cations and anions are missing from the lattice. So, the crystal remains neutral, e.g. $$NaCl.$$
2.
In a closed flask of $$5\,L,$$ $$1.0\,g$$ of $${H_2}$$ is heated from $$300$$ to $$600 K.$$ Which statement is not correct?
Here, volume is constant and mass of hydrogen gas is also fixed, therefore the number of moles remains same. Now as the temperature increases, then pressure also increases. This will lead to more collisions among the gaseous molecules and hence, the energy of molecules increases.
3.
If the ratio of masses of $$S{O_3}$$ and $${O_2}$$ gases confined in a vessel is 1 : 1, then the ratio of their partial pressures would be
Let $$m$$ be the mass of $$S{O_3}$$ and $${O_2}$$ enclosed in the vessel.
Number of moles of $$S{O_3} = \frac{m}{{80}}$$
Number of moles of $${O_2} = \frac{m}{{32}}$$
Partial pressure of $$S{O_3},{P_A} = \frac{m}{{80}} \times \frac{{R \times T}}{V}$$
PartiaI pressure of $${O_2},{P_B} = \frac{m}{{32}} \times \frac{{R \times T}}{V}$$
Now, $$\frac{{{P_A}}}{{{P_B}}} = \frac{m}{{80}} \times \frac{{32}}{m} = \frac{2}{5}$$
Hence, ratio of partial pressure of $$m\,g$$ of $$S{O_3}$$ and $${O_2}$$ is 2 : 5.
4.
Two vessels containing gases $$A$$ and $$B$$ are interconected as shown in the figure. The stopper is opened, the gases are allowed to mix
homogeneously. The partial pressures of $$A$$ and $$B$$ in the mixture will be, respectively
5.
$$\alpha ,v$$ and $$u$$ represent most probable velocity, average velocity and root mean square velocity respectively of a gas at a particular temperature.
The correct order among the following is
6.
Pressure remaining the same, the volume of a given mass of an ideal gas increases for
every degree centigrade rise in temperature by definite fraction of its volume at
According to Charle’s law “the volume of a fixed mass of a gas increases or decreases by $$\frac{1}{{273.15}}$$ of its volume at $${0^ \circ }C$$ for each degree rise or fall of temperature, if pressure is kept constant”.
7.
A closed container contains equal number of moles of two gases $$X$$ and $$Y$$ at a total pressure of $$710\,mm$$ of $$Hg.$$ If gas $$X$$ is removed from the mixture, the pressure will
A liquid below its melting point, is present in solid state and above its melting point, is present in vapour (gaseous) state, so a liquid can exist between melting point and boiling point.
9.
The fraction of total volume occupied by the atoms present in a simple cube is
The root mean square velocity of gas molecule at $$STP$$ is given by
$${U_{rms}} = \sqrt {\frac{{3RT}}{M}} $$
∴ As the molar mass of gas increases, then $${U_{rms}}$$ will decrease, so the order of $${U_{rms}}$$ of these gases is
$$HBr < {O_2} < {N_2} < {H_2}$$