Which of the following processes have a δs > 0? which of the following processes have a > 0? 2hcl(g) → h2(g) + cl2(l) cesium chloride dissolves in pure water lithium fluoride forms from its elements 2nh3(g) + co2(g) → nh2conh2(aq) + h2o(l) all of the above processes have a δs > 0.

 b)  cesium chloride dissolves in pure water

Explanation:

Entropy is the measure of randomness or disorder of a system. If a system moves from  an ordered arrangement to a disordered arrangement, the entropy is said to decrease and vice versa.

is positive when randomness increases and is negative when randomness decreases.

a)

As one mole of the gas is converted to liquid, the randomness of particles decreases and hence   is negative and .

b)  cesium chloride dissolves in pure water:

As solid is converted to aqueous state and ions are formed, the randomness of particles increases and hence   is positive and

c) lithium fluoride forms from its elements :

As molecules combine to form a single product, the randomness of particles decreases and hence   is negative and

d)

As gas is converted to liquid, the randomness of particles decreases and hence   is negative and

acid rain does not usually kill trees directly. instead, it is more likely to weaken the trees by damaging their leaves, limiting the nutrients available to them, or poisoning them with toxic substances slowly released from the soil. the main atmospheric pollutants that affect trees are nitrates and sulphates.