A closed vessel with rigid walls contains 1 mol of $${}_{92}^{238}U$$ and 1 mol of air at 298 K. Considering complete decay of $${}_{92}^{238}U$$ to $${}_{82}^{206}Pb$$, the ratio of the final pressure to the initial pressure of the system at 298 K is

In dilute aqueous H₂SO₄, the complex diaquodioxalatoferrate(II) is oxidized by $$MnO_4^-$$. For this reaction, the ratio of the rate of change of [H⁺] to the rate of change of $$[MnO_4^-]$$ is

The periodic table consists of 18 groups. An isotope of copper, on bombardment with protons undergoes a nuclear reaction yielding element X as shown below. To which group, element X belongs in the periodic table?

$${}_{29}^{63}Cu$$ + $${}_1^1H$$ $$\to$$ $$6{}_0^1n$$ + $${}_2^4\alpha $$ + 2$${}_1^1H$$ + X

An organic compound undergoes first-order decomposition. The time taken for its decomposition to 1/8 and 1/10 of its initial concentration are t_1/8 and t_1/10 respectively. What is the value of $$\left[ {{{{t_{1/8}}} \over {{t_{1/10}}}}} \right] \times 10$$? ($${\log _{10}}2 = 0.3$$)