Answer: 625 kj/mol
Explanation:
As shown below this expression gives the activation energy of the reverse reaction:
EA reverse reaction = EA forward reaction + | enthalpy change |
1) The activation energy, EA is the difference between the potential energies of the reactants and the transition state:
EA = energy of the transition state - energy of the reactants.
2) The activation energy of the forward reaction given is:
EA = energy of the transition state - energy of [ NO2(g) + CO(g) ] = 75 kj/mol
3) The negative enthalpy change - 250 kj / mol for the forward reaction means that the products are below in the potential energy diagram, and that the potential energy of the products, [NO(g) + CO2(g) ] is equal to 375 kj / mol - 250 kj / mol = 125 kj/mol
4) For the reverse reaction the reactants are [NO(g) + CO2(g)], and the transition state is the same than that for the forward reaction.
5) The difference of energy between the transition state and the potential energy of [NO(g) + CO2(g) ] will be the absolute value of the change of enthalpy plus the activation energy for the forward reaction:
EA reverse reaction = EA forward reaction + | enthalpy change |
EA reverse reaction = 375 kj / mol + |-250 kj/mol | = 375 kj/mol + 250 kj/mol = 625 kj/mol.
And that is the answer, 625 kj/mol
The mass of the piece of lead is calculated using the below formula
Q(heat)= mC delta T
Q = 78.0 j
M=mass =?
C=specific heat capacity ( 0.130 j/g/c
delat T=change in temperature = 9.0 c
by making M the subject of the formula
M = Q/ c delta T
M= 78.0 j/ 0.130 j/g/c x 9.0 c = 66.7 g of lead
to the proper number of significant figures) to the following? (12.67+19.2)(3.99)/(1.36+ 11.366).
1. Answer: C. The objects' temperatures have both changed by the same amount.
Explanation:
An object is said to be in thermal equilibrium when the objects have attained same temperature. Heat transfer from hotter object to colder one in contact takes place until the temperature of the two are equal. It is not necessary that the temperature of both the objects changes by same amount. After attainment of thermal equilibrium, the temperature of the objects stop changing and the tiny particles of the object move at the same rate.
Hence, the objects' temperatures have both changed by the same amount. is not necessarily true for two objects in thermal equilibrium.
2. Answer: C. Objects are made of tiny particles, and their motion depends on the temperature.
Explanation:
Kinetic theory of heat states that the kinetic energy of constituent particles determine the temperature of the object. The statement that best explains this is Objects are made of tiny particles, and their motion depends on the temperature.
