The reaction CH_4 (g) + Cl_2 (g) → CH_3 Cl(g)
+ HCl(g) has ΔH = −25 kcal and bond
dissociation energy of C − Cl, H − Cl,
C − H and Cl − Cl is given as 84 kcal/mol,
103 kcal/mol, x kcal/mol and y kcal/mol
respectively. Given x : y = 9 : 5, then
bond energy of Cl − Cl bond in kcal/mol
is
Consider the system shown in the
figure. Initially the system was in rest.
(i) Find the acceleration of block if man
climbs the rod with acceleration a (w.r.t.
rod)
(ii) If the man climb to the top of the
rod then find the distance moved by the
block.
The standard enthalpy of formation of
gaseous H_2 O at 298 K is −241.82 kJ
mol^(−1) . Estimate its value of 100°C given
the following values of the molar heat
capacities at constant pressure:
H_2 O(g) : 35.58 JK^(−1) mol^(−1) , H_2 (g) :
28.84 J mol^(−1) K^(−1) and O_2 (g) : 29.37 J
mol^(−1) K^(−1) . Assume heat capacity to be
independent of temperature.
A baloon filled with helium rises against
gravity increasing its potential energy.
The speed of the baloon also increases
as it rises. How do you reconcile this
with the law of conservation of
mechanical energy? You can neglect
viscous drag of air and assume that
density of air is constant.
A rocket accelerates straight up by
ejecting gas downwards. In a small
time interval Δt, it ejects a gas of mass
Δm at a relative speed u. Calculate KE
of the entire system at t + Δt and t and
show that the device that ejects gas
does work = ((1/2))Δmu^2 in this time
interval (neglect gravity).
A particle of mass m strikes on ground
with angle of incidence 45°. If coefficient
of restitution, e = (1/(√2)) , find the velocity
after impact and angle of reflection.
ΔH_f ^o of N_2 O is 82 kJ/mol and bond
energy for N_2 , N = N, O = O and N = O
bonds are 946, 418, 498 and 607 kJ/mol
respectively, then resonance energy of
N_2 O is
A train weighing 100 metric ton is
running on a level track with a uniform
speed of 72 km h^(−1) . If the frictional
resistance amounts to 0.5 kg per metric
ton, find the power of the engine.
A body of mass 0.3 kg is taken up an
inclined plane of length 10 m and
height 5 m, and then allowed to slide
down to the bottom again. The
coefficient of friction between the body
and the plane is 0.15. What is the
kinetic energy of the body at the end of
the trip?