Answer:
The isotopic mass of 41K is 40.9574 amu
Explanation:
Step 1: Data given
The isotopes are:
39K with an isotopic mass of 38.963707u and natural abundance of 93.2581%
40K with an isotopic mass of 39.963999u
41K wit natural abundance of 6.7302 %
Average atomic mass =39.098 amu
Step 2: Calculate natural abundance of 40 K
100 % - 93.2581 % - 6.7302 %
100 % = 0.0117 %
Step 3: Calculate isotopic mass of 41K
39.098 = 38.963707 * 0.932581 + 39.963999 * 0.000117 + X * 0.067302
39.098 = 36.33681 + 0.0046758 + X * 2.067302
X = 40.9574 amu
The isotopic mass of 41K is 40.9574 amu
Answer:
C
Explanation:
A negative deltaH means that the reaction has to give up heat in order to happen. You have to treat deltaH as a reactant. So the question is do you need to add heat to the reactants to make the products. If you do, deltaH is plus.
Heat is required to make a solid go to a gas. deltaH is plus. A is not the answer.
A lot of heat is required for B (something like 400 Kj / mole. Like A, deltaH is plus and B is not the answer.
C: The liquid has to give up heat in order for the this reaction to take place. C is the answer.
D requires heat. It is not the answer.
The (B) answer (B) is (B) (B) (B)
Answer:
0.071L
Explanation:
From the question given, we obtained the following data:
Molarity of HCl = 2.25 M
Mass of HCl = 5.80g
Molar Mass of HCl = 36.45g/mol
Number of mole of HCl =?
Number of mole = Mass /Molar Mass
Number of mole of HCl = 5.8/36.45 = 0.159mole
Now, we can obtain the volume required as follows:
Molarity = mole /Volume
Volume = mole /Molarity
Volume = 0.159mole/ 2.25
Volume = 0.071L