21.

Which of the following property does not correspond to the order HI < HBr < HCl < HF ?

• Thermal stability

• Reducing power

• Ionic character

• Dipole moment

According to Faraday's first law

• $\mathrm{w} = \frac{ 96500 \times \mathrm{E}}{\mathrm{I} \times \mathrm{t}}$

• $\mathrm{w} = \frac{ \mathrm{I} \times \mathrm{t} \times \mathrm{E}}{96500}$

• $\mathrm{E}=\frac{\mathrm{I} \times \mathrm{t} \times 96500}{\mathrm{w}}$

• $\mathrm{E} = \frac{ \mathrm{I} \times \mathrm{w}}{\mathrm{t} \times 96500}$

Unit of decay constant of radioactive disintegration is

• time

• min^-2

• time^-1

• time mol^-1

A first order reaction is given as A $\to$ products. Its integrated equation is

• $\mathrm{k} =\frac{ 2.303}{\mathrm{t}}\log \frac{ \mathrm{a}-\mathrm{x}}{\mathrm{a}}$

• $\mathrm{k} = \frac{1}{\mathrm{t}} \log \frac{\mathrm{a}}{\mathrm{a}-\mathrm{x}}$

• $\mathrm{k} = \frac{2.303}{\mathrm{t}} \log \frac{\mathrm{a}}{\mathrm{a}-\mathrm{x}}$

• $-\mathrm{k} = \frac{1}{\mathrm{t}} \log \frac{\mathrm{a} -\mathrm{x}}{\mathrm{a}}$

Which of the following does not contain any coordinate bond?

• H₃O⁺

• ${\mathrm{BF}}_4^{-}$

• ${\mathrm{HF}}_2^{-}$

• ${\mathrm{NH}}_4^{+}$

The standard reduction potential for Fe²⁺/Fe and Sn²+/Sn electrodes are - 0.44 and- 0.14 V respectively. For the cell reaction,  ${\mathrm{Fe}}^{+} + \mathrm{Sn} \to \mathrm{Fe} + {\mathrm{Sn}}^{2+}$  the standard emf is

• + 0.30 V

• - 0.58 V

• + 0.58 V

• - 0.30 V

Most common oxidation states shown by cerium are

• +2, +4

• +3, +4

• +3, +5

• +2, +3

TiI₄  on heating gives 

• TiI₂ + I₂

• Ti + 2I₂

• TiI₃+ 1/2 I₂

• None of these

Which of the following phosphorus oxyacids can act as a reducing agent?

• H₃PO₃

• H₃PO₄

• H₂P₂O₆

• H₄P₂O₇

Which of the following transitions involves maximum amount of energy?

• ${{\mathrm{M}}^{-}}_{\left(\mathrm{g}\right)\hspace{0.17em}}\to {\mathrm{M}}_{\left(\mathrm{g}\right)}$

• ${\mathrm{M}}_{\left(\mathrm{g}\right)} \to {\mathrm{M}}_{\left(\mathrm{g}\right)}^{+}$

• ${\mathrm{M}}_{\left(\mathrm{g}\right)}^{+} \to {\mathrm{M}}_{\left(\mathrm{g}\right)}^{2+}$

• ${\mathrm{M}}_{\left(\mathrm{g}\right)}^{2+} \to {\mathrm{M}}_{\left(\mathrm{g}\right)}^{3+}$