It would be the controlled variable, which is a baseline to compare your other variables too.
Hope this helps!
Answer:
Explanation:
Variation allows some individuals within a population to adapt to the changing environment. ... Some new alleles increase an organism's ability to survive and reproduce, which then ensures the survival of the allele in the population.
Explanation:
Average atomic mass of Chlorine = 35.45 amu
The percentage of isotopes is the percentage abundance.
This is given by;
Average atomic mass = (Mass of isotope * Percentage abundance of 35/17 Cl) + (Mass of isotope * Percentage abundance 37/17 Cl)
Let percentage abundance of 35/17 Cl = x
Then percentage abundance of 37/17 Cl = 1 - x
Putting the values in the equation;
35.45 = (35 * x) + (37 * (1-x))
35.45 = 35x + 37 - 37x
35.45 - 37 = 35x - 37x
- 1.55 = -2x
x = 1.55 / 2 = 0.775
Percentage abundance of 35/17 Cl = 0.775 * 100 = 77.5%
Percentage abundance of 37/17 Cl = (1 - 0.775) * 100 = 22.5%
Answer:
∆H= <u>438 KJ/mol</u>
Explanation:
First, we have to find the <u>energy bond values</u> for each compound:
-) Cl-Cl = 243 KJ/mol
-) F-F = 159 KJ/mol
-) F-Cl = 193 KJ/mol
If we check the reaction we can calculate the <u>number of bonds</u>:
In total we will have:
-) Cl-Cl = 1
-) F-F = 3
-) F-Cl = 6
With this in mind. we can calculate the <u>total energy for each bond</u>:
-) Cl-Cl = (1*243 KJ/mol) = 243 KJ/mol
-) F-F = (3*159 KJ/mol) = 477 KJ/mol
-) F-Cl = (6*193 KJ/mol) = 1158 KJ/mol
Now, we can calculate the total energy of the <u>products</u> and the <u>reagents</u>:
Reagents = 243 KJ/mol + 477 KJ/mol = 720 KJ/mol
Products = 1158 KJ/mol
Finally, to calculate the total enthalpy change we have to do a <u>subtraction</u> between products and reagents:
∆H= 1158 KJ/mol-720 KJ/mol = <u>438 KJ/mol</u>
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I hope it helps!