List of top Chemistry Questions

Sodium extract of Lassaigne?? solution is treated with, $FeSO_4, FeCl_3$ and $dil.H_2SO_4$ to get a blood red colour. Which of the following is probable organic compound?

Sodium carbonate can be manufactured by Solvay??s process but potassium carbonate cannot be prepared because

Soaps do not work in hard water containing calcium and magnesium ions because

Soap mixed with water below critical micelle concentration behaves as

$SO_2$ and $NO_2$ cause polluted by increasing

$SO_2$ is one of the air pollutants. $SO_2$

$ {SnCl2}$ gives a precipitate with a solution of $ {HgCl2}$. In this process $ {HgCl2}$ is

Smelting is usually carried out in

$ {SnCl2 + 2HgCl2 -> }$$\underset{\text{White ppt.}}{ {(A)}}$ $ {(A) + SnCl2 -> }$$\underset{\text{Grey}}{ {(B)}}$ A and B are

Six moles of an ideal gas performs a cycle shown in figure. If the temperature are $T_A = 600\, K, T_B = 800\, K, T_C = 2200 \,K$ and $T_D = 1200\, K$, the work done per cycle is approximately

$S_N1$ reaction is fastest in

$S_N2$ mechanism is involved in the following substitution :

Same amount of electric current is passed through solutions of $AgNO_3$ and HCl. If 1.08 g of silver is obtained in the first case, the amount of hydrogen liberated at S.T.P. in the second case is

$S_{N}1$ reaction is favoured by

Roasting is generally done in case of the following

Roasting of copper pyrite ores is for the following purpose

Refractory metals are used in construction of furnaces because

Relative decrease in V.P. of an aqueous solution of NaCl is 0.167. Number of moles of NaCl presentin 180 g of $H_2O$ is

Reductive ozonolysis of benzene produces

Reductive ozonolysis of o-xylene gives

Red phosphorus and hydrogen iodide reduce carboxylate ions to

Red phosphorus is less reactive than yellow phosphorus because

Reduction of aldehyde with HI and P give

Recognise the figure and find out the correct matching.

Read the passage given below and answer the question The hydrogen-like species $Li^{2+}$ is in a spherically symmetric state $S_1$ with one radial node. Upon absorbing light the ion undergoes transition to a state $S_2$. The state $S_2$ has one radial node and its energy is equal to the ground state energy of the hydrogen atom. Energy of the state $S_1$ in units of the hydrogen atom ground state energy is