With what velocity should an $\mathrm{\alpha }$-particle travel towards the nucleus of a copper atom to arrive at a distance of 10^-13m from the nucleus of the copper atom?(K = 9x 10⁹ Nm²/C² (Mass of $\mathrm{\alpha }$-particle = 6.64 x 10^-27kg).

• 634 x 10⁶ ms^-1

• 634 x10⁵ ms^-1

• 5.34 x 10⁶ ms^-1

• 534 x 10⁵ ms^-1

What is the ratio of the velocities of CH₄ and O₂ molecules so that they are associated with de-Broglie waves of equal wavelengths?

• 1:2

• 2: 1

• 3: 2

• 1: 2

What is the value of the spin quantum number of the last electron ford d⁹ -configuration ?

• 0

• $-\frac{1}{2}$

• $\frac{1}{2}$

• 1

Nitrogen forms stable N₂ molecule, but phosphorus is converted to P₄ from P₂ because

• $\mathrm{p\pi }-\mathrm{p\pi }$ bonding is strong in phosphorus 

• $\mathrm{p\pi }-\mathrm{p\pi }$  bonding is weak in phosphorus 

• double bond is present in phosphorus

• single P-P bond is weaker than N-N bond

In which of the following reactions will $∆$U be equal to $∆$H?

• ${\mathrm{H}}_2\left(\mathrm{g}\right) +\frac{1}{2}{\mathrm{O}}_2\left(\mathrm{g}\right)\to {\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)$

• ${\mathrm{H}}_2\left(\mathrm{g}\right) + {\mathrm{I}}_2\left(\mathrm{g}\right) \to 2\mathrm{HI}\left(\mathrm{g}\right)$

• ${\mathrm{N}}_2{\mathrm{O}}_4\left(\mathrm{g}\right) \to 2{\mathrm{NO}}_2\left(\mathrm{g}\right)$

• $2{\mathrm{SO}}_4\left(\mathrm{g}\right) + {\mathrm{O}}_2\left(\mathrm{g}\right) \to 2{\mathrm{SO}}_3\left(\mathrm{g}\right)$

What is the conjugate base of OH ?

• O₂

• H₂O

• O^-

• O^2-

An amorphous solid (X) burns in air to form a gas (Y) which turns lime water milky. This gas decolarises aqueous solution of acidified KMnO₄ gas (Y)reacts with oxygen to give another gas (Z) which is responsible for acid rain. X, Y and Z are

• X	Y	Z
  C	CO	CO2

• X	Y	Z
  S	SO2	SO3

• X	Y	Z
  P	P2O3	P2O5

• X	Y	Z
  S	SO3	H2SO4

A black power when heated with conc. HCl gives a greenish yellow gas. The gas acts as an oxidising and a bleaching agent. When it is passed are slaked lime, a white power is formed which is a ready source of gas. The black powder and white power respectively are

• KClO₃ and NaClO₃

• MnO₂ and CaCOCl₂

• MnO₂ and KClO₃

• MnCl₄ and COCl₂

Which of the following is an organometallic compound?

• Lithium methoxide

• Lithium acetate

• Lithium dimethylamide

• Methyl lithium

The major product obtained in the reaction