Calculate number of electrons present in 9.5 g of ${\mathrm{PO}}_4^{3-}$:

The total no. of neutrons present in 54 mL ${\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)$ are:

The volume of a drop of water is 0.0018 mL then the number of water molecules present in two drop of water at room temperature is:

Which of the following combinations illustrates the law of reciprocal proportions?

Carbon and oxygen combine to form two oxides, carbon monoxide and carbon dioxide in which the ratio of the weights of carbon and oxygen is respectively 12 : 16 and 12 : 32. These figures illustrate the:

The formula of an acid is ${\mathrm{HXO}}_2.$ The mass of 0.0242 moles of the acid is 1.657 g. The atomic weight of X is -

A 6.85 g sample of the hydrates $\mathrm{Sr}{\left(\mathrm{OH}\right)}_2.{\mathrm{xH}}_2\mathrm{O}$ is dried in an oven to give 3.13 g of anhydrous $\mathrm{Sr}{\left(\mathrm{OH}\right)}_2$. The value of x is - 

(Atomic weights : Sr=87.60, O=16.0, H=1.0)

The sulphate of the metal M contains 9.87% of M. This sulphate is isomorphous with ${\mathrm{ZnSO}}_4.7{\mathrm{H}}_2\mathrm{O}$. The atomic weight of M is:

Sulphur burns according to the reaction

                                   $\frac{1}{8}{\mathrm{S}}_8\left(\mathrm{s}\right)+{\mathrm{O}}_2\left(\mathrm{g}\right) \stackrel{}{\to } {\mathrm{SO}}_2\left(\mathrm{g}\right)$
What volume of air, at 1 atm and 273 K, containing 21%  oxygen by volume is required to completely burn sulphur $\left({\mathrm{S}}_8\right)$ present in 200 g of sample? (This sample contains 20% inert material which does not burn)

Phosphoric acid $\left({\mathrm{H}}_3{\mathrm{PO}}_4\right)$ prepared in a two step process.

(1) ${\mathrm{P}}_4+5{\mathrm{O}}_2 \stackrel{}{\to } {\mathrm{P}}_4{\mathrm{O}}_{10}$
(2) ${\mathrm{P}}_4{\mathrm{O}}_{10}+6{\mathrm{H}}_2\mathrm{O} \stackrel{}{\to } 4{\mathrm{H}}_3{\mathrm{PO}}_4$

We allow 62g of phosphorus to react with react with excess oxygen which form ${\mathrm{P}}_4{\mathrm{O}}_{10}$ in 85% yield. In the step (2) reaction 90% yield of ${\mathrm{H}}_3{\mathrm{PO}}_4$ is obtained. Produced mass of ${\mathrm{H}}_3{\mathrm{PO}}_4$ is:

100 mL of ${\mathrm{H}}_2{\mathrm{SO}}_4$ solution having molarity of 1M and density 1.5 g/mL is mixed with 400 mL of water. The molarity of the ${\mathrm{H}}_2{\mathrm{SO}}_4$ solution will be: (final density is 1.25 g/mL )

The molar mass of diacidic organic Lewis base (B), if 12 g of chloroplatinate salt $\left({\mathrm{BH}}_2{\mathrm{PtCl}}_6\right)$ on ignition produced 5 gm residue of Pt,will be -

Equivalent weight of ${\mathrm{H}}_3{\mathrm{PO}}_2$ when it disproportionate into ${\mathrm{PH}}_3$ and ${\mathrm{H}}_3{\mathrm{PO}}_3$ is:

What volume of ${\mathrm{O}}_2\left(\mathrm{g}\right)$ measured at 1 atm and 273 K will be formed by the action of 100 mL of 0.5 N KMnO₄ on hydrogen peroxide in an acid solution?

The skeleton equation for the reaction is

${\mathrm{KMnO}}_4+{\mathrm{H}}_2{\mathrm{SO}}_4+{\mathrm{H}}_2{\mathrm{O}}_2$$\to {\mathrm{K}}_2{\mathrm{SO}}_4+{\mathrm{MnSO}}_4+{\mathrm{O}}_2+{\mathrm{H}}_2\mathrm{O}$

The weight of a mixture containing $\mathrm{HCl}$ and ${\mathrm{H}}_2{\mathrm{SO}}_4$ is 0.1 g. On treatment with an excess of an ${\mathrm{AgNO}}_3$ solution, reacted with this acid mixture gives 0.1435 g of $\mathrm{AgCl}$. Weight% of the ${\mathrm{H}}_2{\mathrm{SO}}_4$ is mixture is:

A solution of ${\mathrm{Na}}_2{\mathrm{S}}_2{\mathrm{O}}_3$ is standardized iodometrically against 0.167 g of ${\mathrm{KBrO}}_3$. This process requires 50 mL of the ${\mathrm{Na}}_2{\mathrm{S}}_2{\mathrm{O}}_3$ solution. What is the normality of the ${\mathrm{Na}}_2{\mathrm{S}}_2{\mathrm{O}}_3$?

The ${\mathrm{NH}}_3$ evolved due to complete conversion of N from 1.12 g sample of protein was absorbed in 45 mL of 0.4 N ${\mathrm{HNO}}_3$. The excess acid required 20 mL of 0.1 N $\mathrm{NaOH}$. The % N in the sample is:

Suppose the elements X and Y combine to form two compounds XY₂ and X₃Y₂. If 0.1 moles of XY₂ weighs 10 g and 0.05 mole of X₃Y₂ weighs 9 g, the atomic weight of X and Y ,respectively, will be

Which of the following parameters is temperature dependent?

A mixture of 2.3 g formic acid and 4.5 g oxalic acid is treated with conc. ${\mathrm{H}}_2{\mathrm{SO}}_4$. The evolved gaseous mixture is passed through KOH pellets. Weight (in g) of the remaining product at STP will be

What is the mole fraction of the solute in a 1.00 m aqueous solution?

A mixture of gases contains H₂ and O₂ gases in the ratio of 1 : 4 (w/w). The molar ratio of the two gases in the mixture will be