Physical Chemistry Answers

c) Two particles A and B with masses of 3 kg and 2 kg respectively, travel in a straight line towards each other. Both particles have a speed of
4 ms-1 before they collide. Answer the following:
i) JI the two particles stick together upon collision, calculate the final speed of the combined particles after the collision;
ii) If particle A continues moving in the same original direction after the collision with a speed of 0.4 ms-1, calculate the speed of particle B after the collision.

d) Calculate the centripetal force acting on an object of mass 250 g travelling with a constant speed of 3.5 ms-1 on a circular path of radius 37 mm

a) A particle undergoes simple harmonic motion with an angular velocity of 5 rad s-1 and an amplitude of 50 cm. If it starts with maximum forward amplitude at I = 0, find:
i) the displacement at I = 10 s;
ii) the acceleration at I = 6 s.
iii) the velocity at I = 2 s.

b) i) A 5 kg mass undergoes simple harmonic motion on a spring with a force constant of 70 Nm-1. If the amplitude is 3 m, calculate the maximum velocity.
ii) Briefly explain the meaning of the terms damping and resonance
in relation to systems oscillating with simple harmonic motion.

An object of mass 12 kg is pushed up a frictionless slope with a 35° angle to the horizontal over a distance of 22 m by an 82 N force. Calculate the following:

i) the work done on the object;
ii) the potential and kinetic energy imparted to the object.

a) An object of mass 45 g moves in a circular orbit of radius 6 cm with a speed of 18.5 cm s-1. Calculate the following:

i) the circular frequency of the object;
ii) the angular speed and centripetal acceleration of the object;
iii) the centripetal force acting on the object.


b) A mass of 25 kg is attached to a single spring and undergoes simple harmonic motion with a time period of 11.1 s. Calculate the following:

i) the acceleration of the spring when displaced 15 cm from the equilibrium position;
ii) the force constant of the single spring;
iii) the resulting force constant if two equivalent springs are connected in series and in parallel,
iv) the time period of oscillation for the two springs joined in series. How does this value compare to the single spring?

Calculate the entropy change when 36 g of ice is heated at standard pressure from 230 K to 320 K. Take the molar heat
capacities at constant pressure, Cp,m, of water and ice to be
75.3 and 37.7 J mol 1 -1 respectively, and the molar enthalpy
of fusion of ice to be 6.02 kJ mol-^. The molar mass of water is 18.0 g mol-1, and ice melts at a temperature of 273.15 K。

b) For a reaction of the type:
B Products
the initial rate of the reaction (i.e. the rate at time t = 0; denoted Ro) Was measured at T=298 K for different values of the initial concentration of the reactant B (denoted [B]o). The measured data are:

[B]o / mol dm—3 3.0 6.0 9.0 12.0 1 5.0
Ro / mol dms s- 1 21.8 87.1 1 96 348 545


Using the method of initial rates and drawing an appropriate graph, determine the order of the reaction and the value of the rate constant for the reaction at T -- 298 K.

a) A particle A of mass 1.5 kg travels in a straight line with a velocity of
3.5 ms-1. Particle A collides with a stationary particle B of mass 2.5 kg.
i) Following the collision, if A and B move away from each other with
a velocity of v m s-1 and 4s m s-1 respectively find the value of V';
ii) Determine if the collision is elastic or inelastic.


b) An object is projected with an initial velocity of 32 m s-1 at an angle of 42° to the horizontal, hitting point B on the same horizontal. Calculate:

i) The time taken for the object to move from point A to point B;
ii) The distance travelled from point A to point B.






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Physical properties of an element depend upon which of the following?

atomic number
atomic mass
atomic radii
atomic volume
atomic radius

To precipitate as Ag2S(s), all Ag+ present in 250 ml of a saturated solution of AgBrO3 requires 3.36 cm3 ofH2S(g) measured at STP (Assuming H2S is enough soluble in water). Ksp of AgBrO3 is :[Ksp(Ag2S) = 10–50, Ka(H2S) = 10–21]

The symbols in the following list that represent state functions or are equivalent to state functions are:

1. S.

2. H.

3. qv.

4. w.


A) 1 only
B) 1, 2, and 3 only
C) 3 and 4 only
D) 1 and 2 only
E) 2 only