Answer:
Mass = 785.9 g
Explanation:
Given data:
Atoms of gold = 2.4 × 10²⁴ atoms
Mass of gold = ?
Solution:
First of all we will convert the number of atoms into moles.
2.4 × 10²⁴ atoms × 1 mol/ 6.02 × 10²³ atoms
number of moles = 3.99 mol
Now we will determine the mass of gold.
Mass = number of moles × molar mass
Mass = 3.99 mol × 196.97 g/mol
Mass = 785.9 g
According to the task, you are proveded with patial pressure of CO2 and graphite, and here is complete solution for the task :
At first you have to find n1 =moles of CO2 and n2 which are moles of C
<span>The you go :
</span>

n1 n2 0
-x -x +2x

After that you have to use the formula

Then you have to solve x, and for that you have to use <span>RT/V
And to find total values:</span>

I am absolutely sure that this would be helpful for you.
Answer: The ion that contribute to water hardness are:
--> a. Ca2+
--> b. (HCO)3^- and
--> c. Mg2+
While K+ DOES NOT contribute to water hardness.
Explanation:
WATER in chemistry is known as a universal solvent. This is so because it is polar in nature and dissolves most inorganic solutes and some polar organic solutes to form aqueous solutions. It is composed of elements such as hydrogen and oxygen in the combined ratio of 2:1.
Water is said to be HARD if it does not lather readily with soap. There are two types of water hardness:
--> Permanent hardness: This is mainly due to the presence of CALCIUM and MAGNESIUM ions in the form of soluble tetraoxosulphate(VI) and chlorides. These ions are removed by adding washing soda or caustic soda.
--> Temporary hardness: This is due to the presence of calcium HYDROGENTRIOXOCARBONATES. It can be removed by boiling and using slaked lime.
Therefore from the above given ions, Ca2+,(HCO)3^- and Mg2+ contributes to water hardness.
[ H+]=10-pH
it become
[H+]=0.1