It is the mass of one mole of the substance.
Answer: Option (4) is the correct answer.
Explanation:
When sulfuric acid reacts with calcium hydroxide then it results in the formation of calcium sulfate and water.
The chemical reaction for the same will be as follows.
Thus, we can conclude that 
salt is produced when sulfuric acid and calcium hydroxide react completely.
Answer : The value of 
of the weak acid is, 4.72
Explanation :
First we have to calculate the moles of KOH.
Now we have to calculate the value of of the weak acid.
The equilibrium chemical reaction is:
Initial moles 0.25 0.03 0
At eqm. (0.25-0.03) 0.03 0.03
= 0.22
Using Henderson Hesselbach equation :
![pH=pK_a+\log \frac{[Salt]}{[Acid]}](https://tex.z-dn.net/?f=pH%3DpK_a%2B%5Clog%20%5Cfrac%7B%5BSalt%5D%7D%7B%5BAcid%5D%7D)
![pH=pK_a+\log \frac{[HK]}{[HA]}](https://tex.z-dn.net/?f=pH%3DpK_a%2B%5Clog%20%5Cfrac%7B%5BHK%5D%7D%7B%5BHA%5D%7D)
Now put all the given values in this expression, we get:
Therefore, the value of of the weak acid is, 4.72
Annually 126.0 million metric tons of soil nutrients are lost.
<u>Explanation</u>:
- By the given data we can identify the loss of soil nutrients in the United States. In the first year, a total of 1.0 million soil nutrients are lost.
- After that in the second year, the loss has doubled. 10.0 million metric tons of soil nutrients are lost.
- In the third year, 16.0 million soil nutrients are lost in the US.
- In the final year, 90.0 million soil nutrients are lost. It is a very huge loss. By calculating all the above , a total 126.0 million of soil nutrients in the US are lost annually.
It doesn't take much energy to remove one electron from a sodium atom to form an Na+ ion with a filled-shell electron configuration. The first ionization energy of magnesium is larger than sodium because magnesium has one more proton in its nucleus to hold on to the electrons in the 3s orbital.
