List of top Chemistry Questions

At 300 K a first order reaction is 50 % completed in 10 minutes. What is the rate constant value of the reaction at this temperature? \((\log 2 = 0.3)\)}

In which of the following equilibrium reaction, pressure does not influence the equilibrium at constant temperature?}

Using stock notation, match the oxidation number against metal in its compound.}

The oxidation number of oxygen in \(O_2\), \(O_2F_2\) and \(RbO_2\) are respectively}

Which of the following statement is incorrect?}

100 cm\(^3\) of an aqueous solution of a protein contains 1.5 g of the protein. The osmotic pressure of such a solution at 300 K is found to be \(4.5 \times 10^{-3}\) bar. The molar mass of the protein is \([R = 0.083 \text{ L atm mol}^{-1}\text{ K}^{-1}]\)}

At equilibrium, \([N_2] = 1.5 \times 10^{-3}M\), \([O_2] = 2 \times 10^{-3}M\) and \([NO] = 3 \times 10^{-3}M\) at 800 K in a closed vessel. The \(K_c\) for the equilibrium \(N_2(g) + O_2(g) \rightleftharpoons 2NO(g)\) at 800 K is}

For the equilibrium what is the value of \(\log_{10}K\) at 298 K? \((\Delta_r H^\circ = -54.07 \text{ kJ mol}^{-1}, \Delta_r S^\circ = 10 \text{ J K}^{-1}\) and \(2.303RT = 5705)\)}

The number and type of bonds between nitrogen and three oxygen atoms in \(HNO_3\) by Lewis representation is}

Which of the following set of compounds does not follow octet rule?}

Four elements and their electronegativity values (Pauling Scale) are given below. Match the element with its electronegativity value.}

Which of the following statement is NOT the postulate of VSEPR theory?}

An ideal gas is allowed to expand from 1 L to 10 L against a constant external pressure of 1 bar. The work done is [1 bar = 100 J]}

The percentage composition of carbon in methane is}

Which of the following statement is incorrect?}

Which of the following d-orbital does not have four lobes?}

The IUPAC symbol of the element with atomic number 110 is}

The correct increasing order of the ionic radii of the isoelectronic species \(O^{2-}, N^{3-}, F^{-}, Mg^{2+}, Na^{+}\) and \(Al^{3+}\) is}

The set of elements which has exceptional electronic configurations not obeying Aufbau principle is}

An aromatic compound A on treatment with ethanolic NaCN forms compound B which on reduction with $H_2/Ni$ gives a compound C of molecular formula $C_8H_{11}N$. The compounds A, B and C are

Match the following reactions with the corresponding reagents} Reactions \hspace{3cm} Reagents} (a) Oxidation of secondary alcohols to ketones \hspace{0.3cm} (i) $85%\,H_3PO_4,\ 440K$} (b) Dehydration of secondary alcohols to alkenes \hspace{0.1cm} (ii) $Na_2Cr_2O_7/H_2SO_4$} (c) Reduction of ketones to secondary alcohols \hspace{0.5cm} (iii) Chromic anhydride} (d) Oxidation of phenol to benzoquinone \hspace{0.2cm} (iv) $NaBH_4$

Which of the following is NOT correctly matched for the compound and use mentioned below?

Which of the following amine has lowest $pK_b$ value in aqueous phase?

The linkage formed between 5' and 3' carbon atoms of the pentose sugar in nucleotides is

In aldol condensation reaction, 1,3-diphenylprop-2-en-1-one is obtained as major product in the reaction between