Moles of ammonium sulfide = 5.80 mol
The formula of ammonium sulfide is (NH₄)₂S
So each molecule of ammonium sulfide has (4 x 2) or 8 atoms of H
One mole of ammonium sulfide has 8 moles of H
5.80 mol of ammonium sulfide has (8 x 5.8) or 46.4 moles of H
As per the definition of Avogadro's number, 1 mole = 6.022 x 10²³ atoms
46.4 moles of H x (6.022 x 10²³ atoms/ 1 mole of H)
= 2.8 x 10²⁵ H atoms
Therefore, 2.8 x 10²⁵ H atoms are in 5.80 mol of ammonium sulfide.
Answer:
The result is 3.859 in which we use four significant figures.
Explanation:
We start by solving the mathematical operation :

The result for the operation is 3.859438 but the numbers in the operation are given with four significant figures and that is why we are going to use four significant figures to express the result
To express 3.859438 with four significant figures we use the first four digits that appear from left to right starting by the first digit that is different to zero
In this case : 3.859 will be the result with four significant figures.
We also use a rule that says : To decide if the last significant figure remains the same we look for the value of the digit at its right.
If that number is greater than or equal to 5 ⇒ we sum one to the last significant figure
For example 3.859738 = 3.860 with four significant figures because the ''7'' is greater that 5
If that number is less than 5 ⇒ the last significant figure remains the same
In our case : 3.859438 = 3.859 because ''4'' is less than ''5''
Answer:
At transform plate boundaries, two plates move in opposite direction. Transform faults are the site of massive earthquakes. The San Andreas Fault is the boundary between the Pacific and North American plates.
It shows mass is not created nor lost but re arranged
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