Some Basic Concepts of Chemistry — JEE Advanced PYQs

The stoichiometric reaction of 516 g of dimethyldichlorosilane with water results in a tetrameric cyclic product X in 75% yield. The weight (in g) of X obtained is ____.

[Use, molar mass …

If the reaction sequence given below is carried out with 15 moles of acetylene, the amount of the product D formed (in g) is ____.

The yields of $\mathbf{A},\mathbf{B},\mathbf{C}$ and $\mathbf{D}$ are given in parentheses.
[Given : Atomic mass of …

To check the principle of multiple proportions, a series of pure binary compounds $\left({\mathrm{P}}_{\mathrm{m}}{\mathrm{Q}}_{\mathrm{n}}\right)$ were analyzed and their composition is tabulated below. The correct option(s) is(are)
| Compound | Weight % of P | Weight % of Q || …

For the following reaction scheme, percentage yields are given along the arrow:

$\mathbf{x}$ g and $\mathbf{y}$ g are mass of $\mathbf{R}$ and $\mathbf{U}$, respectively.
(Use: Molar mass (in ${\mathrm{g}\mathrm{mol}}^{-1}$) of H, C and O as 1, 12 and 16, respectively)

The value of …

Aluminium reacts with sulfuric acid to form aluminium sulfate and hydrogen. What is the volume of hydrogen gas in liters (L) produced at 300 K and 1.0 atm pressure, when 5.4 g of aluminium and 50.0 mL of 5.0 M sulfuric acid are combined for the reaction?
(Use molar mass of alumin …

The mole fraction of urea in an aqueous urea solution containing 900 g of water is 0.05. If the density of the solution is $1.2\mathrm{g}{\mathrm{cm}}^{-3}$, the molarity of urea solution is ____

(Given data : Molar masses of urea and water are $60\mathrm{g}{\mathrm{mol}}^{-1}$ …

If the value of Avogadro number is $6.023\times 10^{23}{\mathrm{mol}}^{-1}$ and the value of Boltzmann constant is $1.380\times 10^{-23}\mathrm{J}{\mathrm{K}}^{-1}$, then the number of significant digits in the calculated value of the universal gas constant is

A compound ${\mathbf{H}}_2\mathbf{X}$ with molar weight of $80g$ is dissolved in a solvent having density of $0.4\mathrm{g}{\mathrm{ml}}^{-1}$. Assuming no change in volume upon dissolution, the molality of a 3.2 molar solution is

$29.2\%(\mathrm{w}/\mathrm{w})\mathrm{HCl}$ stock solution has a density of $1.25\mathrm{g}{\mathrm{mL}}^{-1}$. The molecular weight of HCl is $36.5\mathrm{g}{\mathrm{mol}}^{-1}$. The volume (mL) of stock solution required to prepare a 200 mL solution of 0.4 M HCl i …

Dissolving 120 g of urea (mol. wt. 60) in 1000 g of water gave a solution of density $1.15\mathrm{g}/\mathrm{mL}$. The molarity of the solution is

A student performs a titration with different burettes and finds titre values of 25.2 mL, 25.25 mL, and 25.0 mL. The number of significant figures in the average titre value is

Given that the abundances of isotopes ${}^{54}\mathrm{Fe},{}^{56}\mathrm{Fe}$ and ${}^{57}\mathrm{Fe}$ are 5%, 90% and 5%, respectively, the atomic mass of Fe is