<u>Answer:</u>
<em>Silver tarnishing as the silver metal reacts with sulphur is a chemical change.</em>
<u>Explanation:</u>
Tarnishing is the process of chemical change occurring on the surface of objects leading to corrosion or other defects on the surface. The remaining options like dilution, eroding is a physical change where the concentration of salt and rock particles will be decreased, respectively.
Similarly for soil drying also the concentration of water will be decreased leading to a physical change from wetty or dry soil.
But the last option which indicates tarnishing of silver metal on reaction with sulphur is a chemical process as the surface of silver metal will be reacting to sulphur and leads to lose of electrons which leads to corrosion of the surface or tarnishing of silver.
Answer:
The timber companies removing all the trees from entire hillside when they are harvesting logs is a practice that could cause the following when it is time to plant in spring:
1. It could affect the quality of plant needed nutrients in the soil and beneficial microorganism population in the soil which could impact negatively the planting season.
2. Trees serves as protection of soil nutrients against wind erosions, so the soil nutrients would be affected.
The farmers tilling the soil means preparing the soil for a farming season as the following effect:
1. Helps control weed for the planting season.
2. This practice could further encourage soil erosion if not done well.
3. Tilling the soil could make leftover plants from the felling of trees mix well with the soil and also add nutrients to the soil when they decay.
<u>Answer:</u> The equilibrium concentration of bromine gas is 0.00135 M
<u>Explanation:</u>
We are given:
Initial concentration of chlorine gas = 0.0300 M
Initial concentration of bromine monochlorine = 0.0200 M
For the given chemical equation:
<u>Initial:</u> 0.02 0.03
<u>At eqllm:</u> 0.02-2x x 0.03+x
The expression of 
for above equation follows:
![K_c=\frac{[Br_2]\times [Cl_2]}{[BrCl]^2}](https://tex.z-dn.net/?f=K_c%3D%5Cfrac%7B%5BBr_2%5D%5Ctimes%20%5BCl_2%5D%7D%7B%5BBrCl%5D%5E2%7D)
We are given:
Putting values in above equation, we get:
Neglecting the value of x = -0.96 because, concentration cannot be negative
So, equilibrium concentration of bromine gas = x = 0.00135 M
Hence, the equilibrium concentration of bromine gas is 0.00135 M
