List of top Chemistry Questions

A piece of wood from an' archaeological sample has $5.0$ counts $\min ^{-1}$ per gram of $C-14$, while a fresh sample of wood has a count of $15.0 \,min ^{-1} \,g ^{-1}$. If half-life of $C-14$ is $5770\, yr$, the age of the archaeological sample is

Dissolving $120 \,g$ of a compound of (mol. wt. $60$) in $1000 \,g$ of water gave a solution of density $1.12 \,g/mL$. The molarity of the solution is :

Equal masses of $H_2, O_2$ and methane have been taken in a container of volume V at temperature $27^\circ$C in identical conditions. The ratio of the volumes of gases ${H_2 : O_2 :CH_4}$ would be

When 22.4 L of $H_{2(g)}$ is mixed with 11.2 L of $Cl_{2(g)}$, each at STP, the moles of $HCl_{(g)}$ formed is equal to

Sulphur sol is a type of

$25 \, cm^3$ of oxalic acid completely neutralised $0.064\, g$ of sodium hydroxide. Molarity of the oxalic acid solution is

Identity Z in the sequence of reactions, $CH_3 CH_2 CH=CH_2 \xrightarrow{HBr/H_2 O_2}Y \xrightarrow{C_2H_5 ON_a}Z$

Similarity in chemical properties of the atoms of elements in a group of the Periodic table is most closely related to :

Which series of reactions correctly represents chemical relations related to iron and its compound?

Among the following oxoacids, the correct decreasing order of acidic strength is

Which of the following statements about $Na_2O_2$ is not correct?

The protein component of a holoenzyme is known as

The compressibility factor $(Z)$ of one mole of a van der Waals gas of negligible $�a�$ value is

$\left(_{32}Ge^{76}, _{34}Se^{76}\right)$ and $\left(_{14}Si^{30}, _{16}S^{32}\right)$ are examples of

The volume of ethyl alcohol (density $1.15\, g/cc$) that has to be added to prepare $100\,cc$ of $0.5\, M$ ethyl alcohol solution in water is

The order of decreasing ease of abstraction of Hydrogen atoms in the following molecule is

For a given exothermic reaction, $K_p$ and $K_p'$ are the equilibrium constants at temperatures $T_1$ and $T_2$, respectively. Assuming that heat of reaction is constant in temperature range between $T_1$ and $T_2$, it is readily observed that :-

In the Kjeldahl's method for estimation of nitrogen present in a soil sample, ammonia evolved from $0.75\, g$ of sample neutralized $10\, mL$ of ${1 \, M \, H_2SO_4}$. The percentage of nitrogen in the soil is :

$Be^{2+}$ is isoelectronic with which of the following ions?

The pair of compounds that can exist together is

The formal potential of $Fe ^{3+} / Fe ^{2+}$ in a sulphuric acid and phosphoric acid mixture $\left(E^{\circ}=+0.61 \,V \right)$ is much lower than the standard potential $\left(E^{\circ}=+0.77 \,V \right) .$ This is due to

Among the following statements about the molecules $X $ and $Y$, the one (s) which is (are) correct is (are)

The $4^{th}$ higher homologue of ethane is

The structure of $XeF_6$ is experimentally determined to be distorted octahedron. Its structure according to VSEPR theory is

The disease that occurs in mature adult human being due to deficiency of calciferol is