JEE Main 2003 — Inorganic Chemistry

Ammonia forms the complex ion $\left[\mathrm{Cu}\left(\mathrm{NH}_3\right)_4\right]^{2+}$ with copper ions in alkaline solutions but not in acidic solutions. What is the reason for it?

Concentrated hydrochloric acid when kept in open air sometimes produces a cloud of white fumes. The explanation for it is that

For making good quality mirrors, plates of float glass are used. These are obtained by floating molten glass over a liquid metal which does not solidify before glass. The metal used can be

Graphite is a soft solid lubricant extremely difficult to melt. The reason for this anomalous behaviour is that graphite

In curing cement plasters water is sprinkled from time to time. This helps in

In the coordination compound, $\mathrm{K}_4\left[\mathrm{Ni}(\mathrm{CN})_4\right]$, the oxidation state of nickel is

One mole of the complex compound $\mathrm{Co}\left(\mathrm{NH}_3\right)_5 \mathrm{Cl}_3$, gives 3 moles of ions on dissolution in water. One mole of the same complex reacts with two moles of $\mathrm{AgNO}_3$ solution to yield two moles of $\mathrm{AgCl}$ (s). The structure of the complex is

The atomic numbers of vanadium $(\mathrm{V})$, Chromium $(\mathrm{Cr})$, manganese $(\mathrm{Mn})$ and iron $(\mathrm{Fe})$ are respectively 23 , 24,25 and 26 . Which one of these may be expected to have the highest second ionization enthalpy?

The number of d-electrons retained in $\mathrm{Fe}^{2+}$ (At.no.of $\mathrm{Fe}=26$ ) ion is

The pair of species having identical shapes for molecules of both species is

The radionucleide ${ }_{90}^{234} \mathrm{Th}$ undergoes two successive $\beta$-decays followed by one $\alpha$-decay. The atomic number and the mass number respectively of the resulting radionucleide are

The radius of $\mathrm{La}^{3+}$ (Atomic number of $\mathrm{La}=57$ ) is $1.06 Å$. Which one of the following given values will be closest to the radius of $\mathrm{Lu}^{3+}$ (Atomic number of $\mathrm{Lu}=71$ )?

What may be expected to happen when phosphine gas is mixed with chlorine gas?

What would happen when a solution of potassium chromate is treated with an excess of dilute nitric acid?

Which one of the following compounds has the smallest bond angle in its molecule?

Which one of the following is an amphoteric oxide?

Which one of the following nitrates will leave behind a metal on strong heating?

Which one of the following pairs of molecules will have permanent dipole moments for both members?

Which one of the following substances has the highest proton affinity?