Advertisements
Advertisements
Question
A reaction between N2 and O2 takes place as follows:
\[\ce{2N2 (g) + O2 (g) ⇌ 2N2O (g)}\]
If a mixture of 0.482 mol of N2 and 0.933 mol of O2 is placed in a 10 L reaction vessel and allowed to form N2O at a temperature for which Kc = 2.0 × 10-37, determine the composition of equilibrium mixture.
Solution
Let x moles of N2(g) take part in the reaction. According to the equation, x/2 moles of O2 (g) will react to form x moles of N2O(g). The molar concentration per litre of different species before the reaction and at the equilibrium point is:
| 2N2(g) | + | O2(g) | ↔ | 2N2O(g) | |
| Initial mole/litre: | `0.482/10` | `0.933/10` | Zero | ||
| Mole/litre at equation point: | `(0.482 - x)/10` | `(0.933 - x/2)/10` | `x/10` |
The value of equilibrium constant (2.0 x 10-37) is extremely small. This means that only small amounts of reactants have reacted. Therefore, is extremely small and can be omitted as far as the reactants are concerned.
Applying Law of chemical Equilibrium `"K"_"c" = ["N"_2"O"("g")]^2/(["N"_2("g")]^2["O"_2("g")])`
`2.0 xx 10^(-37) = (x/10)^2/((0.482/10)^2 xx(0.933/10))`
`= (0.01 x^2)/(2.1676 xx 10^(-4))`
`x^2 = 43.352 xx 10^(-40)` or `x = 6.6 xx 10^(-20)`
As x is extermely small it can be neglected
Thus in the equilibrium mixture
Molar conc. of `"N"_2` = 0.0482 mol `"L"^(-1)`
Molar conc. of `"O"_2` = 0.0933 mol `"L"^(-1)`
Molar conc. of `"N"_2"O"` = `0.1 xx x`
`= 0.1 xx 6.6 xx 10^(-20)` mol `"L"^(-1)`
`= 6.6 xx 10^(-21) " mol L"^(-1)`
APPEARS IN
RELATED QUESTIONS
Write the expression for the equilibrium constant, Kc for the following reactions:
\[\ce{2Cu(NO3)2 (s) ⇌ 2CuO (s) + 4NO2 (g) + O2 (g)}\]
Write the expression for the equilibrium constant, Kc for the following reactions:
\[\ce{CH3COOC2H5(aq) + H2O(l) ⇌CH3COOH (aq) + C2H5OH (aq)}\]
Write the expression for the equilibrium constant, Kc for following reactions:
\[\ce{Fe^{3+}(aq) + 3OH^-(aq) ⇌ Fe(OH)3(s)}\]
What is the equilibrium concentration of each of the substances in the equilibrium when the initial concentration of ICl was 0.78 M?
\[\ce{2 ICl(g) ⇌ I2(g) + Cl2(g)}\]; KC = 0.14
Kp = 0.04 atm at 899 K for the equilibrium shown below. What is the equilibrium concentration of C2H6 when it is placed in a flask at 4.0 atm pressure and allowed to come to equilibrium?
\[\ce{C2H6 (g) ⇌ C2H4 (g) + H2 (g)}\]
Calculate a) ΔG°and b) the equilibrium constant for the formation of NO2 from NO and O2 at 298 K
\[\ce{NO(g) + 1/2 O_2 (g) <=> NO_2(g)}\]
where ΔfG⊝ (NO2) = 52.0 kJ/mol
ΔfG⊝ (NO) = 87.0 kJ/mol
ΔfG⊝ (O2) = 0 kJ/mol
Does the number of moles of reaction products increase, decrease or remain same when each of the following equilibria is subjected to a decrease in pressure by increasing the volume?
\[\ce{3Fe (s) + 4H2O (g) ⇌ Fe3O4 (s) + 4H2 (g)}\]
Predict which of the following reaction will have the appreciable concentration of reactants and products:
- \[\ce{Cl2 (g) ⇌ 2Cl (g)}\] Kc = 5 ×10–39
- \[\ce{Cl2 (g) + 2NO (g) ⇌ 2NOCl (g)}\] Kc = 3.7 × 108
- \[\ce{Cl2 (g) + 2NO2 (g) ⇌ 2NO2Cl (g)}\] Kc = 1.8
For the reaction \[\ce{H2 (g) + I2 (g) ⇌ 2HI (g)}\], the standard free energy is ∆GΘ > 0. The equilibrium constant (K ) would be ______.
For the reaction : \[\ce{N2 (g) + 3H2 (g) ⇌ 2NH3 (g)}\]
Equilibrium constant `K_C = ([NH3]^2)/([N_2][H_2]^3)`
Some reactions are written below in Column I and their equilibrium constants in terms of Kc are written in Column II. Match the following reactions with the corresponding equilibrium constant
| Column I (Reaction) | Column II (Equilibrium constant) |
| (i) \[\ce{2N2 (g) + 6H2 (g) ⇌ 4NH3 (g)}\] | (a) `2K_c` |
| (ii) \[\ce{2NH3 (g) ⇌ N2 (g) + 3H2 (g)}\] | (b) `K_c^(1/2)` |
| (iii) \[\ce{1/2 N2 (g) + 3/2 H2 (g) ⇌ NH3 (g)}\] | (c) `1/K_c` |
| (d) `K_c^2` |
Match standard free energy of the reaction with the corresponding equilibrium constant.
| Column I | Column II |
| (i) ∆GΘ > 0 | (a) K > 1 |
| (ii) ∆GΘ > 0 | (b) K = 1 |
| (iii) ∆GΘ = 0 | (c) K = 0 |
| (d) K < 1 |
The stepwise formation of [Cu(NH3)4]2+ is given below:
\[\ce{Cu^{2+} + NH3 <=>[K1] [Cu(NH3)]^{2+}}\]
\[\ce{[Cu(NH3)]^{2+} + NH3 <=>[K2] [Cu(NH3)2]^{2+}}\]
\[\ce{[Cu(NH3)2]^{2+} + NH3 <=>[K3] [Cu(NH3)3]^{2+}}\]
\[\ce{[Cu(NH3)3]^{2+} + NH3 <=>[K4] [Cu(NH3)4]^{2+}}\]
The value of stability constants K1, K2, K3 and K4 are 104, 1.58 × 102, 5 × 103 and 102 respectively. The overall equilibrium constant for dissociation of [Cu(NH3)4]2+ is x × 10−12. The value of x is ______. (Rounded-off to the nearest integer)
For the reaction \[\ce{A(g) <=> B(g)}\] at 495 K, ΔG° = −9.478 kJ mol−1
If we start the reaction in a closed container at 495 K with 22 millimoles of A, the amount of B in the equilibrium mixture is ______ millimoles. (Round off to the Nearest Integer).
[R = 8.314 J mol−1 K−1; ln 10 = 2.303]
An equilibrium system for the reaction between hydrogen and iodine to give hydrogen iodide at 765 K in a 5 litre volume contains 0.4 mole of hydrogen, 0.4 mole of iodine and 2.4 moles of hydrogen iodide.
\[\ce{H2 + I2 <=> 2HI}\]
The equilibrium constant for the reaction is:
Sulphide ion in alkaline solution reacts with solid sulphur to form polysulphide ions having formula, \[\ce{S^{2-}2}\], \[\ce{S^{2-}3}\], \[\ce{S^{2-}4}\], etc. if K1 = 12 for \[\ce{S + S^{2-} <=> S^{2-}2}\] and K2 = 132 for \[\ce{2S + S^{2-} <=> S^{2-}3}\], K3 = ______ for \[\ce{S + S^{2-}2 <=> S^{2-}3}\].
For which of the following Kp is less than Kc?
The equilibrium constant for the reaction is ______ × 1026.
\[\ce{Fe + CuSO4 <=> FeSO4 + Cu}\] at 25°C.
Given `"E"_("Fe"//"Fe"^(2+))^0` = 0.44 V
`"E"_("Cu"//"Cu"^(2+))^0` = - 0.337 V
The decomposition of N2O4 to NO2 was carried out in chloroform at 280°C. At equilibrium, 0.2 mol of N2O4 and 2 × 10−3 mol of NO2 were present in 2 ℓ of the solution. The equilibrium constant for the reaction \[\ce{N2O4 <=> 2NO2}\] is ______.
