Chemistry Test-...

The product of the following reaction is

A freshly prepared sample of a radio-isotope of half-life \(1386\) second has activity \(10^{3}\) dps. Given that \(ln 2=0.693\), the fraction of the initial number of nuclei (expressed in nearest integer percentage) that will decay in the first \(80\) second after preparation of the sample is:

The compound that does not produce nitrogen has by the thermal decomposition is:

The heat change associated with reactions at constant volume is due to the difference in which property of the reactants and the products?

In which of the following changes is an electron added to antibonding \(\left(\pi^{*}\right)\)orbital?

There are two radioactive substances \(A\) and \(B\). Decay constant of \(B\) is two times that of A. Initially, both have equal number of nuclei. After \(n\) half lives of \(A\), rate of disintegration of both are equal. The value of \(n\) is:

Which of the following is pyrimidine base?

Which among the following is a heterogeneous mixture?

Nitrobenzene on reaction with conc. \(\mathrm{HNO}_{3} / \mathrm{H}_{2} \mathrm{SO}_{4}\) at \(80-100^{\circ} \mathrm{C}\) forms which one of the following products?

According to Dalton's atomic theory, an atom: