Temperature of a gas is t K. What would be the temperature at which volume and pressure, both will reduced to half of the initial values?

• $\frac{t}{2}$

• $\frac{t}{4}$

• $\frac{t}{3}$

• $\frac{t}{8}$

What will be the number of waves formed by a Bohr electron in one complete revolution in its second orbit?

• Three

• Two

• One

• Zero

3.

At 27°C, one mole of an ideal gas is compressed isothermally and reversibly from a pressure of 2 atm to 10 atm. Choose the correct option from the following

• Change in internal energy is positive

• Heat is negative

• Work done is - 965.84 cal

• All are incorrect

Choose the incorrect statement about noble gas?

• Boiling point increases with increasing atomic mass

• Helium has least tendency to form compound

• Noble gases have some value of electron affinity

• Xenon has maximum number of compounds

Aqueous solution of AlCl₃ is acidic towards litmus while of NaCl is not. The correct reason behind this is

• AlCl₃, furnishes OH^- ion in the solution

• AlCl₃, furnishes H⁺ ion in the solution

• AlCl₃, furnishes both H⁺ well as OH^- ion in the solution

• AlCl₃, is the salt of strong base and strong acid

The melting point of solid substances is directly proportional to pressure acting on them. However, ice-melts at a temperature lower than its usual melting point, when the pressure increases. This is because

• ice is not a true solid

• the bonds break under pressure

• ice is less denser than water

• pressure generates heat

Work is being performed, when a weight lifter lifts a base ball off a weight rack. This is due to

• magnetic attraction

• gravity

• electrostatic repulsion

• mechanical force

Beryllium differs in properties from other elements of its own group but shows resemblance with aluminium because of

• relatively bigger ionic radius and high polarising power of Be

• relatively smaller ionic radius and high polarising power of Be

• relatively bigger ionic radius is the only reason behind this

• None of the above

Choose the correct statement from the following

• ${\mathrm{NH}}_4^{+}$ and CH₄ are not isoelectronic species

• BF₃ does not have dipole moment

• O - Cl - O obeys octet rule

• O^- in O₃ is Sp³-hybridised

Which of the following pair of compounds will have three sp² -hybrid orbitals?

• SO₂, CH₄

• SO₃, C₂H₄

• BF₃, SF₃

• ${\mathrm{I}}_3^{-}$, SF₄