List of top Chemistry Questions

Given below are two statements:
Statement I: [CoBr₄]²⁻ ion will absorb light of lower energy than [CoCl₄]²⁻ ion.
Statement II: In [CoBr₄]²⁻ ion, the energy separation between the two set of d-orbitals is more than [CoCl₄]²⁻ ion.
In the light of the above statements, choose the correct answer from the options given below :
Consider the general reaction given below at 400 K: xA(g) ⇌ yB(g). The values of K___p and K___c are studied under the same condition of temperature but variation in x and y.
(i) K___p = 85.87 and K___c = 2.586
(ii) K___p = 0.862 and K___c = 28.62.
The values of x and y in (i) and (ii) respectively are :

Compound 'P' undergoes the following sequence of reactions : (i) NH₃ (ii) $\Delta$ $\rightarrow$ Q (i) KOH, Br₂ (ii) CHCl₃, KOH (alc), $\Delta$ $\rightarrow$ NC-CH₃. 'P' is : 

Consider the following compounds. Arrange these compounds in a n increasing order of reactivity with nitrating mixture. The correct order is : 

Given, (A) n=5, m___l = -1; (B) n=3, l=2, m___l = -1, m___s = +1/2. The maximum number of electron(s) in an atom that can have the quantum numbers as given in (A) and (B) respectively are :

But-2-yne and hydrogen (one mole each) are separately treated with (i) Pd/C and (ii) Na/liq.NH₃ to give the products X and Y respectively.

Identify the incorrect statements.
A. X and Y are stereoisomers.
B. Dipole moment of X is zero.
C. Boiling point of X is higher than Y.
D. X and Y react with O₃/Zn + H₂O to give different products.
Choose the correct answer from the options given below :

The statements that are incorrect about the nickel(II) complex of dimethylglyoxime are :
A. It is red in colour.
B. It has a high solubility in water at pH = 9.
C. The Ni ion has two unpaired d-electrons.
D. The N – Ni – N bond angle is almost close to 90°.
E. The complex contains four five-membered metallacycles (metal containing rings).
Choose the correct answer from the options given below :
Which of the following statements regarding the energy of the stationary state is true in the following one-electron systems ?

Match List-I with List-II. 

'x' is the product from propenenitrile + $SnCl_2/HCl$ followed by hydrolysis. 'y' is the product from but-2-ene by ozonolysis. Which product is not obtained when 'x' and 'y' react in alkali with heating?
The crystal field splitting energy of $[Co(oxalate)_3]^3-$ complex is 'n' times that of the $[Cr(oxalate)_3]^3-$ complex. Here 'n' is_______ (Assume $\Delta_0 > P$)}

For the thermal decomposition of reactant AB(g), the following plot is constructed. 

The half life of the reaction is 'x' min.
x =_______} min. (Nearest integer)} 
 

500 J of energy is transferred as heat to 0.5 mol of Argon gas at 298 K and 1.00 atm. The final temperature and the change in internal energy respectively are: Given: $R = 8.3\ \text{J K}^{-1}\text{mol}^{-1}$

Given below are two statements:
Statement I: The number of species among \( SF_4 \), \( NH_4^+ \), \( [NiCl_4]^{2-} \), \( XeF_4 \), \( [PtCl_4]^{2-} \), \( SeF_4 \) and \( [Ni(CN)_4]^{2-} \), that have tetrahedral geometry is 3.
Statement II: In the set \( [NO_2] \), \( BeH_2 \), \( BF_3 \), \( AlCl_3 \), all the molecules have incomplete octet around the central atom.
In the light of the above statements, choose the correct answer from the options given below:

At $27^\circ\text{C}$, in presence of a catalyst, activation energy of a reaction is lowered by $10\,\text{kJ mol}^{-1}$. The logarithm of the ratio $\dfrac{k(\text{catalysed})}{k(\text{uncatalysed})}$ is ___.
(Consider that the frequency factor for both the reactions is same)
A hydroxy compound $(X)$ with molar mass $122\,\text{g mol}^{-1}$ is acetylated with acetic anhydride, using a large excess of the reagent ensuring complete acetylation of all hydroxyl groups. The product obtained has a molar mass of $290\,\text{g mol}^{-1}$. The number of hydroxyl groups present in compound $(X)$ is ___.
Consider three metal chlorides $x$, $y$ and $z$, where $x$ is water soluble at room temperature, $y$ is sparingly soluble in water at room temperature and $z$ is soluble in hot water. $x$, $y$ and $z$ are respectively ___.
Given below are statements about some molecules/ions. Identify the CORRECT statements.
A. The dipole moment value of $\mathrm{NF_3}$ is higher than that of $\mathrm{NH_3}$.
B. The dipole moment value of $\mathrm{BeH_2}$ is zero.
C. The bond order of $\mathrm{O_2^{2-}}$ and $\mathrm{F_2}$ is same.
D. The formal charge on the central oxygen atom of ozone is $-1$.
E. In $\mathrm{NO_2}$, all the three atoms satisfy the octet rule, hence it is very stable.
Choose the correct answer from the options given below:

$A \rightarrow D$ is an endothermic reaction occurring in three elementary steps:
(i) $A \rightarrow B \quad \Delta H_i = +\text{ve}$ 
(ii) $B \rightarrow C \quad \Delta H_{ii} = -\text{ve}$ 
(iii) $C \rightarrow D \quad \Delta H_{iii} = -\text{ve}$ 
Which of the following graphs between potential energy (y-axis) versus reaction coordinate (x-axis) correctly represents the reaction profile of $A \rightarrow D$? 

The correct stability order of the following diazonium salts is:

Choose the correct answer from the options given below: 
 

Arrange the following carbanions in the decreasing order of stability:
I. $p$-$\mathrm{Br{-}C_6H_4{-}CH_2^-}$ 
II. $\mathrm{C_6H_5{-}CH_2^-}$ 
III. $p$-$\mathrm{CH_3O{-}C_6H_4{-}CH_2^-}$ 
IV. $p$-$\mathrm{CHO{-}C_6H_4{-}CH_2^-}$ 
V. $p$-$\mathrm{CH_3{-}C_6H_4{-}CH_2^-}$ 
Choose the correct answer from the options given below: 
 

$W$ g of a non-volatile electrolyte solid solute of molar mass $M\,\text{g mol}^{-1}$ when dissolved in $100\,\text{mL}$ water decreases vapour pressure of water from $640\,\text{mm Hg}$ to $600\,\text{mm Hg}$. If aqueous solution of the electrolyte boils at $375\,\text{K}$ and $K_b$ for water is $0.52\,\text{K kg mol}^{-1}$, then the mole fraction of the electrolyte $(x_2)$ in the solution can be expressed as ___.
(Given: density of water $=1\,\text{g mL}^{-1}$, boiling point of water $=373\,\text{K}$)

Match the LIST-I with LIST-II for an isothermal process of an ideal gas system. 

Choose the correct answer from the options given below: 
 

Given below are two statements:
Statement I: C–Cl bond is stronger in $\mathrm{CH_2 = CH{-}Cl}$ than in $\mathrm{CH_3{-}CH_2{-}Cl}$.
Statement II: The given optically active molecule, on hydrolysis, gives a solution that can rotate the plane polarized light.
In the light of the above statements, choose the correct answer from the options given below:

Arrange the following alkenes in the decreasing order of stability:
 
Choose the correct answer from the options given below: