1
JEE Main 2021 (Online) 26th August Evening Shift
Numerical
+4
-1
For water $$\Delta$$vap H = 41 kJ mol$$-$$1 at 373 K and 1 bar pressure. Assuming that water vapour is an ideal gas that occupies a much larger volume than liquid water, the internal energy change during evaporation of water is ___________ kJ mol$$-$$1

[Use : R = 8.3 J mol$$-$$1 K$$-$$1]
2
JEE Main 2021 (Online) 26th August Morning Shift
Numerical
+4
-1
The Born-Haber cycle for KCl is evaluated with the following data :

$${\Delta _f}{H^\Theta }$$ for KCl = $$-$$436.7 kJ mol$$-$$1 ;

$${\Delta _{sub}}{H^\Theta }$$ for K = 89.2 kJ mol$$-$$1 ;

$${\Delta _{ionization}}{H^\Theta }$$ for K = 419.0 kJ mol$$-$$1 ;

$${\Delta _{electron\,gain}}{H^\Theta }$$ for Cl(g) = $$-$$348.6 kJ mol$$-$$1 ;

$${\Delta _{bond}}{H^\Theta }$$ for Cl2 = 243.0 kJ mol$$-$$1

The magnitude of lattice enthalpy of KCl in kJ mol$$-$$1 is _____________ (Nearest integer)
3
JEE Main 2021 (Online) 27th July Evening Shift
Numerical
+4
-1
When 400 mL of 0.2 M H2SO4 solution is mixed with 600 mL of 0.1 M NaOH solution, the increase in temperature of the final solution is __________ $$\times$$ 10$$-$$2 K. (Round off to the nearest integer).

[Use : H+ (aq) + OH$$-$$ (aq) $$\to$$ H2O : $$\Delta$$$$\gamma$$H = $$-$$57.1 kJ mol$$-$$1]

Specific heat of H2O = 4.18 J K$$-$$1 g$$-$$1

density of H2O = 1.0 g cm$$-$$3

Assume no change in volume of solution on mixing.
4
JEE Main 2021 (Online) 27th July Morning Shift
Numerical
+4
-1
For water at 100$$^\circ$$ C and 1 bar,

$$\Delta$$vap H $$-$$ $$\Delta$$vap U = _____________ $$\times$$ 102 J mol$$-$$1. (Round off to the Nearest Integer)

[Use : R = 8.31 J mol$$-$$1 K$$-$$1]

[Assume volume of H2O(l) is much smaller than volume of H2O(g). Assume H2O(g) treated as an ideal gas]
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