Which of the following statements is true.
a. all spontaneous processes are exothermic.
b. all non spontaneous processes are endothermic
c. all spontaneous processes release free energy.
d. entropy always increase in a spontaneous process.

The correct answer is Option C.

Explanation:

Spontaneous reactions are defined as the reactions in which Gibbs free energy change is always negative and when Gibbs free energy change is positive, the reactions are known as non-spontaneous reactions.

Exothermic reactions are the reaction in which enthalpy change is negative and when the enthalpy change is positive, they are known as endothermic reactions.

Spontaneous reactions can be exothermic as well as endothermic.

It is not always that when entropy increases, reaction will be spontaneous. There are cases when the entropy is getting decreased but the reaction is still spontaneous.

Hence, the correct answer is Option C.

first let us lay out the formula for potential

and kinetic energy:

pe = mgh

ke = (mv^2)/2

where: m=mass, v=velocity, g=gravitational

acceleration, h=height

calculating for mass using the known values of

pe:

340j = m (9.81 m/s^2) (50ft) (1m/3.28ft)

m = 2.27 kg

the law of conservation of energy states that

energy is neither created nor destroyed. therefore, the change in kinetic

energy from 50 ft to 35 ft would be equal to the change in potential energy

from 50 ft to 35 ft. however it would be opposite in signs since one is losing

while other is gaining.

ke(35ft) – ke(50ft) = - [ pe(35ft) – pe(50ft]

ke(50ft) = 0 since the brick is initially at rest

ke(35ft) = 340j - 2.27kg (9.81 m/s^2) (35ft)

(1m/3.28 ft)

ke(35ft)

= 102.38 j

the correct answer is b. a strong acid completely dissociates to its ions when dissolved in water. completely dissociates to and ions. a is incorrect because does not fully ionize to and ions and some remain as the compound . c and d are incorrect because, and do not fall into the category of bronsted lowry acids. a bronsted lowry acid is a proton donor and since both molecules do not have a proton to donate they are not bronsted lowry acids. likewise,   if we use the lewis acid definition, they cannot be acids. a lewis acid is an electron pair acceptor. both and have a complete octet so can not accept any electrons which disqualifies them as acids.