List of top Chemistry Questions

How many grams of concentrated nitric acid solution should be used to prepare $250\, mL$ of $2 \cdot 0\, M HNO _{3}$ ? The concentrated acid is $70 \% HNO _{3}$.

Equal weights of $NaCl$ and $KCl$ are dissolved separately in equal volumes of solutions. Molarity of the two solutions will be :

Strong reducing behaviour of $H_3PO_2$ is due to

The alkali metals form salt-like hydrides by the direct synthesis at elevated temperature. The thermal stability of these hydrides decreases in which of the following order?

Among the following four structures $I$ to $IV$, it is true that

For the dissociation reaction, $H _{2}( g ) \rightarrow 2 H ( g ) \quad \Delta H =162 Kcal$, heat of atomisation of $H$ is

The enthalpy of combustion of $2$ moles of benzene at $27^{\circ} C$ differs from the value determined in bomb calorimeter by

$NH_4Cl(s)$ is heated in a test tube. Vapours are brought in contact with red litmus paper, which changes it to blue and then to red. It is because of

Which of the following compounds will not undergo Friedal-Craft's reaction easily?

Arrange in the correct order of stability (decreasing order) for the following molecules :

\(12\, g\) of a nonvolatile solute dissolved in \(108\, g\) of water produces the relative lowering of vapor pressure of \(0.1.\)The molecular mass of the solute is :

A compound with molecular mass $180$ is acylated with $CH_3COCl$ to get a compound with molecular mass $390$. The number of amino groups present per molecule of the former compound is

Bond distance in $HF$ is $9.17 \times 10^{-11}\, m$. Dipole moment of $HF$ is $6.10^4 \times 10^{-30}\, Cm$ . The percentage ionic character in $HF$ will be : (electron charge $= 1.60 \times 10^{-19}\, C$)

Which one of the following molecules is polar?

Monocarboxylic acids are functional isomers of:

A major component of Borsch reagent is obtained by reacting hydrazine hydrate with which of the following ?

A solution of $(-) 1-chloro-1-$phenylethane in toluene racemises slowly in the presence of a small amount of $SbCl_5$, due to the formation of

The Wurtz-Fittig reaction involves condensation of:

An ether (A), $C_5H_{12}O$, when heated with excess of hot concentrated $HI$ produced two alkyl halides which when treated with $NaOH$ yielded compounds (B) and (C). Oxidation of (B) and (C) gave a propanone and an ethanoic acid respectively. The IUPAC name of the ether (A) is :

Arrange the following compounds in the order of decreasing acidity

Glycosidic linkage is actually an :

Which of the following enzyme converts starch into maltose?

Which of the following structures represents thymine?

Natural glucose is termed D-glucose because :

Which one of the following is most stable?