Answer:
- The abundance of 107Ag is 51.5%.
- The abundance of 109Ag is 48.5%.
Explanation:
The <em>average atomic mass</em> of silver can be expressed as:
107.87 = 106.90 * A1 + 108.90 * A2
Where A1 is the abundance of 107Ag and A2 of 109Ag.
Assuming those two isotopes are the only one stables, we can use the equation:
A1 + A2 = 1.0
So now we have a system of two equations with two unknowns, and what's left is algebra.
First we<u> use the second equation to express A1 in terms of A2</u>:
A1 = 1.0 - A2
We <u>replace A1 in the first equation</u>:
107.87 = 106.90 * A1 + 108.90 * A2
107.87 = 106.90 * (1.0-A2) + 108.90 * A2
107.87 = 106.90 - 106.90*A2 + 108.90*A2
107.87 = 106.90 + 2*A2
2*A2 = 0.97
A2 = 0.485
So the abundance of 109Ag is (0.485*100%) 48.5%.
We <u>use the value of A2 to calculate A1 in the second equation</u>:
A1 + A2 = 1.0
A1 + 0.485 = 1.0
A1 = 0.515
So the abundance of 107Ag is 51.5%.
The enthalpy of reaction or ∆H reaction is the difference between the bond energy of the reactants and the bond energy of the products.
<h3>What is ∆H reaction?</h3>
The term ∆H reaction refers to the heat that is evolved or absorbed in a chemical reaction. It is also known as the enthalpy of reaction.
The question is incoherent but I will try to answer as much as possible. Using the values of bond energy, ∆H reaction = Bond energy of reactants - bond energy of products. This will give us the enthalpy of reaction.
Learn more about bond energy: brainly.com/question/1657608
First, we shall calculate the total number of moles present in the final solution.
Number of moles in 0.50 m NaCl = molarity * volume = 0.50 * 3.0 = 1.5 moles.
Number of moles in 0.2777m NaCl = molarity * volume = 0.2777 * 9.0 = 0.24993 moles
Total number of moles = 1.5 + 0.24993 = 1.74993 moles
Second, we shall calculate the total volume of the final solution.
Total volume = 3 + 9 = 12 litres.
The molarity = total number of moles / total volume = 1.74993 / 12 = 0.1458 m
