Answer:
heavier gases - sank to the surface
lighter gases - escaped into space
oxygen - produced through photosynthesis
carbon dioxide - released by volcanoes
Explanation:
Since the formation of the atmosphere on Earth, there has been constant changes in it, gradually leading to the atmosphere that we have nowadays. In the distant past, the atmosphere was much different, and it took lot of time for it to become what it is. The volcanoes with their activity contributed to constant release of carbon dioxide, resulting in the greenhouse effect. The organisms that are able to perform photosynthesis started to release lot of oxygen into the atmosphere, thus setting up better living conditions. The gravity of our planet contributed to the vertical distribution of the gasses, with the heavier being lower, and the lighter ones being further up or released into space.
Volume of each solution : 60 ml 20% and 40 ml 45%
<h3>Further explanation</h3>
Given
20% and 45% acid
100 ml of 30% acid
Required
Volume of each solution
Solution
Molarity from 2 solutions :
Vm Mm = V₁. M₁ + V₂. M₂
m = mixed solution
V = volume
M = molarity
V₁ = x ml
V₂ = (100 - x) ml
Input the value :
100 . 0.3 = x . 0.2 + (100-x) . 0.45
30 = 0.2x+45-0.45x
0.25x=15
x= 60 ml
V₁ = 60 ml
V₂ = 100 - 60 = 40 ml
Explanation:
The reaction equation will be as follows.
Hence, moles of Na = moles of electron used
Therefore, calculate the number of moles of sodium as follows.
No. of moles = 
= 
(as 1 kg = 1000 g)
= 195.65 mol
As, Q = 
where F = Faraday's constant
= 
= 
mol C
Relation between electrical energy and Q is as follows.
E = 
Hence, putting the given values into the above formula and then calculate the value of electricity as follows.
E =
= 
= 
As 1 J = 
kWh
Hence, 
kWh
= 3.39 kWh
Thus, we can conclude that 3.39 kilowatt-hours of electricity is required in the given situation.
Answer: NO2, NO, and O2.
<span>Free radicals are toxic substances produced by the body. In normal circumstances,the body can neutralize but<span>
when the level of these substances is to much,they accumulate
and can generate diseases,
such as osteoporosis and cancer.</span></span>
The balanced chemical equation for the above reaction is as follows ;
Mg + 2HCl —> MgCl2 + H2
The stoichiometry of Mg to HCl is 1:2
This means that 1 mol of Mg reacts with 2 mol of HCl
Equal amounts of both Mg and HCl have been added. One reagent is the limiting reactant and other reactant is in excess.
Limiting reactant is the reagent that is fully used up in the reaction and the amount of Product formed depends on the amount of limiting reactant present.
In this reaction if Mg is the limiting reactant, 4.40 moles of Mg should react with 4.40x2 -8.80 moles of HCl.
But only 4.40 moles of HCl present therefore HCl is the limiting reactant that reacts with 4.40/2 = 2.20 moles of Mg
Stoichiometry of HCl to MgCl2 is 2:1
Since HCl moles reacted -4.40 mol
Then MgCl2 moles formed are 4.40/2 = 2.20 mol of MgCl2
