The good ozone protects us from the UV/ harmful radiations whereas bad ozone is an air pollutant.
Explanation:
- There are two types of ozone layer found in the earth's atmosphere extending from troposphere to stratosphere. They are good ozone and bad ozone.
- Bad ozone as mentioned earlier it is an air pollutant and found in the ground level of earth, most accurately the troposphere. Bad ozone is formed in the ground level of earth's atmosphere by the reaction between nitrogen oxides and organic compounds which are volatile
- The Good ozone is found in the stratosphere layer of the earth's atmosphere. They protect us from harmful radiations. Good ozone layer in the stratosphere of the atmosphere is being destroyed by hydrocarbons, CFCs, and human intervention
Answer: B
. particle size
Explanation:
Let's begin by explaining that a molecular sieve is a device, whose composition allows the absorbtion of molecules that are small enough to pass through its pores, since it is made up of small pores of a precise and uniform size.
Thus, very small molecules manage to pass through the pores of the sieve, while large ones do not.
So, based on this premise, a molecular sieve separates the substances by their size.
Hence, the correct option is B.
Answer:
1.56 mol H₂
Explanation:
Mg₃(Si₂O₅)₂(OH)₂
<em>There are 4 Si moles per Mg₃(Si₂O₅)₂(OH)₂ mol</em>. With that in mind we can <u>calculate how many Mg₃(Si₂O₅)₂(OH)₂ moles are there in the sample</u>, using the <em>given number of silicon moles</em>:
- 3.120 mol Si *
= 0.78 mol Mg₃(Si₂O₅)₂(OH)₂
Then we can <u>convert Mg₃(Si₂O₅)₂(OH)₂ moles into hydrogen moles</u>, keeping in mind that <em>there are 2 hydrogen moles per Mg₃(Si₂O₅)₂(OH)₂ mol</em>:
- 0.78 mol Mg₃(Si₂O₅)₂(OH)₂ * 2 = 1.56 mol H₂
Answer:
d) cut the large sized Cu solid into smaller sized pieces
Explanation:
The aim of the question is to select the right condition for that would increases the rate of the reaction.
a) use a large sized piece of the solid Cu
This option is wrong. Reducing the surface area decreases the reaction rate.
b) lower the initial temperature below 25 °C for the liquid reactant, HNO3
Hugher temperatures leads to faster reactions hence this option is wrong.
c) use a 0.5 M HNO3 instead of 2.0 M HNO3
Higher concentration leads to increased rate of reaction. Hence this option is wrong.
d) cut the large sized Cu solid into smaller sized pieces
This leads to an increased surface area of the reactants, which leads to an increased rate of the reaction. This is the correct option.
