List of top Chemistry Questions

If pH of solution changes from 4 to 5, then the $\text{H}_3\text{O}^+$ion concentration of solution}

What is the wavenumber of the photon emitted during transition from the orbit $\text{n} = 5$ to that of $\text{n} = 2$ in hydrogen atom? $[ \text{R}_\text{H} = 109677\text{ cm}^{-1} ]$}

Which of the following reactions exhibits decrease in entropy?

Find the mass of potassium chlorate required to liberate $5.6 \text{ dm}^3$ of oxygen gas at STP? (molar mass of $\text{KClO}_3 = 122.5\text{ g/mol}$ )}

Rate law for the reaction,
$\text{C}_2\text{H}_5\text{I}_{(g)} \longrightarrow \text{C}_2\text{H}_{4(g)} + \text{HI}_{(g)}$ is $\text{r} = \text{k} [\text{C}_2\text{H}_5\text{I}]$
What is the order and molecularity of this reaction?

Which transition series includes elements Co and Mo respectively?

Identify the element from following such that the last electron is placed in $(\text{n} - 1)\text{d}$ orbital.

Identify pair of complexes that exhibits solvate isomerism?

Which of the following statements is NOT correct regarding voids in lattice structure?

Identify the product ' B ' in the following series of reactions.
Chlorobenzene $\xrightarrow{\text{i) NaOH, 623 K / 150 atm}{\text{ii) H}_3\text{O}^+} \text{A} \xrightarrow{\text{Br}_2\text{ water}} \text{B}$}

For the cell,
$\ominus\text{Zn}_{(s)} | \text{Zn}^{+2}(1\text{M}) || \text{Ag}^{+1}(1\text{M}) | \text{Ag}_{(s)}^\oplus$
If concentration of $\text{Zn}^{+2}$ decreases to $0.1\text{ M}$ at $298\text{ K}$, then emf of cell}

Which solvent from following is used in order to avoid creation of waste and pollution of air?

Half life of a first order reaction is $900\text{ minute}$ at $400\text{ K}$, find its half life at $300\text{ K}$ ?
$\left( \frac{\text{E}_\text{a}}{2.303\text{R}} = 1.3056 \times 10^3 \right)$

What is the total number of donor atoms present in Tetracyanonickelate(II) ion?

Which of the following statements is correct about $\text{O}_2$ and $\text{O}_3$ molecule?

Calculate the concentration of an aqueous solution of non electrolyte at $300\text{ K}$ if its osmotic pressure is $12\text{ atm}$.
$[ \text{R} = 0.0821\text{ atm dm}^3\text{ K}^{-1}\text{ mol}^{-1} ]$

Which of the following is NOT dihydric phenol?

In ionic solid, anions are arranged in ccp array and cations occupy $1/3$ tetrahedral voids. What is the formula of ionic compound?
[Consider $\text{A} = \text{cation}; \text{B} = \text{anion}$]

Which from following carbohydrates produces double quantity of glucose on hydrolysis per mole as compared with sucrose?

Identify example of sorption from following.

Which from following is true according to Gay-Lussac's law?

What is the loss in molar mass when a primary amine is obtained by Hofmann degradation of amide?

Which of the following molecules has a regular geometry as expected?

Which from following pairs of carbohydrates produce equal quantity of glucose on hydrolysis per mole?

Calculate the molal elevation constant of solvent if boiling point of $0.12\text{ m}$ solution is $319.8\text{ K}$ (Boling point of solvent $= 319.5\text{ K}$ )}