List of top Chemistry Questions

Using the standard electrode potentials given below ,predict if the reaction between the following is feasible:
(a) Fe3+(aq) and I- (aq) 
(b) Ag+ (aq) and Cu(s)
(c) Fe3+ (aq) and Cu(s) 
(d) Ag(s) and Fe3+(aq)
(e) Br2(aq) and Fe2+(aq)
What sorts of information can you draw from the following reaction?
(CN)2( g)+2OH−(aq)\(\rightarrow\)CN−(2aq)+CNO−(aq)+H2O(l)
The solubility product constant of Ag2CrO4 and AgBr are 1.1×10–12 and 5.0×10–13 respectively. Calculate the ratio of the molarities of their saturated solutions.
Balance the following redox reactions by ion-electron method: 
(a)MnO4- (aq) + I - (aq) → MnO2(s) + I2(s) (in basic medium)
(b) MnO4- (aq) + SO2(g) → Mn2+(aq) +HSO4- (aq) (in acidic solution)
(c) H2O2(aq)+Fe2+(aq) → Fe3+ (aq) + H2O (l) (in acidic solution)
(d) Cr2O72-+ SO2(g) → Cr3+ (aq) +SO42- (aq) (in acidic solution)
Which of the following carbocation is most stable?
Determine the molecular formula of an oxide of iron, in which the mass per cent of iron and oxygen are 69.9 and 30.1, respectively.
Explain the principle of paper chromatography.
Differentiate between the principle of estimation of nitrogen in an organic compound by (i) Dumas method and (ii) Kjeldahl’s method.
Discuss the chemistry of Lassaigne’s test.
Why is Wurtz reaction not preferred for the preparation of alkanes containing odd number of carbon atoms? Illustrate your answer by taking one example
Calculate the entropy change in surroundings when \(1.00\ mol\) of \(H_2O(l)\) is formed under standard conditions. \(∆_fH^Θ= –286\ kJ mol^{-1}\).
Comment on the thermodynamic stability of \(NO(g)\), given
\(\frac 12N_2(g) +\frac 12O_2(g)→NO(g); \ \ \ \ ∆_rH^Θ= 90\ kJ mol^{-1}\)
\(NO(g) +\frac 12 O_2(g)→NO_2(g);\ \ \  ∆_rH^Θ= –74\ kJ mol^{-1}\)
The equilibrium constant for a reaction is \(10\). What will be the value of \(∆G^Θ\)?
\(R= 8.314\ JK^{-1} mol^{-1}, T=300\ K\)
For the reaction
\(2A(g)+B(g)→2D(g)\)
\(∆U^Θ= -10.5\ kJ\) and \(∆S^Θ= -44.1\ JK^{-1}\).
Calculate \(∆G^Θ\) for the reaction, and predict whether the reaction may occur spontaneously.
For the reaction, \(2Cl(g)→Cl_2(g)\), what are the signs of \(∆H\) and \(∆S\) ?
For the reaction at \(298\ K\),
\(2A+B→C\)
\(∆H = 400\ kJ mol^{-1}\) and \(∆S = 0.2\ kJ K^{-1} mol^{-1}\)
At what temperature will the reaction become spontaneous considering \(∆H\) and \(∆S\) to be constant over the temperature range.
Calculate the enthalpy change for the process
\(CCl_4(g) → C(g) + 4Cl(g)\)
and calculate bond enthalpy of \(C-Cl\) in \(CCl_4(g)\).
\(∆_{vap}H^Θ(CCl_4) = 30.5\ kJ mol^{-1}\).
\(∆_fH^Θ(CCl_4)= –135.5\ kJ mol^{-1}\).
\(∆_aH^Θ (C)= 715.0\ kJ mol^{-1}\),    where \(∆_aH^Θ\) is enthalpy of atomisation.
\(∆_aH^Θ (Cl_2) = 242\ kJ mol^{-1}\).
Calculate the standard enthalpy of formation of \(CH_3OH(l)\) from the following data.
\(CH_3OH (l) +\frac 32 O_2(g)→CO_2(g)+2H_2O (l)\) ;  \( ∆_rH^Θ= –726 \ kJ mol^{–1}\),
\(C(graphite)+O_2(g)→CO_2(g)\);  \(∆_cH^Θ = –393 \ kJ mol^{–1}\),
\(H_2(g)+\frac 12 O_2(g)→H_2O (l)\);  \(∆_f H^Θ= –286 kJ mol^{–1}\)
Given, \(N_2(g) + 3H_2(g)→2NH_3(g)\); \(∆_rH^Θ=-92.4\ kJ mol^{–1}\)
What is the standard enthalpy of formation of \(NH_3\) gas?
Enthalpies of formation of CO(g), CO2(g), N2O(g) and N2O4(g) are –110, – 393, 81 and 9.7 kJ mol-1 respectively. Find the value of ∆rH for the reaction.
\(N_2O_4(g) + 3CO(g) → N_2O(g) + 3CO_2(g)\)
In Lassaigne’s test for nitrogen in an organic compound, the Prussian blue color is obtained due to the formation of 
The reaction CH3CH2I + KOH(aq) \(\rightarrow\) CH3CH2OH + KI is classified as 
Enthalpy of combustion of carbon to CO2 is –393.5 kJ mol–1. Calculate the heat released upon formation of 35.2 g of CO2 from carbon and dioxygen gas.
Calculate the enthalpy change on freezing of \(1.0\ mol\) of water at \(10.0°C\) to ice at \(-10.0°C\). \(∆_{fus}H = 6.03\ kJ mol^{–1}\) at \(0°C\).
\(C_p [H_2O(l)] = 75.3\ J mol^{–1}K^{–1}\)
\(C_p [H_2O(s)] = 36.8 \ J mol^{–1}K^{–1}\)
The best and latest technique for isolation, purification and separation of organic compounds is