Answer:
Concentration = 1.32 m
Boiling point = 
Explanation:
Let the boiling point of two solutions = T
Let the molal concentration of the two solutions= m
The relation between elevation in boiling point and molal concentration is:

i) For benzene

....(1)
ii) For carbon tetrachloride

...(2)
Equating the two equations:

Putting value of "m" in equation "1"

The solution would be like
this for this specific problem:
<span><span>
E</span>=</span><span>mc</span>ΔT<span> <span>
= (</span>15<span> g</span><span>)(</span>1.91<span> <span>J<span><span>g∘</span>C</span></span>)(</span>25<span><span> ∘</span>C</span>−15<span><span> ∘</span>C</span><span>)
</span></span>= 28.65 * 10
= 286.5
<span>
I hope this helps and if you have any further questions, please don’t hesitate
to ask again. </span>
Answer:
²⁵ Mg = 10.00%
²⁶ Mg = 11.0%
Explanation:
Given that:
Magnesium ²⁴Mg has an abundance of 78.99%
Hence, (100 - 78.99)% = 21.01%
21.01% is the abundance of ²⁵ Mg and ²⁶ Mg
Suppose,
²⁵ Mg = x
²⁶ Mg = (21.01 - x)%
Then;
avg. atomic mass = 
where the avg. atomic mass = 24.3050
∴

2430.5 = 2440.46915 -0.9968 x
0.9968x = 2440.46915 - 2430.5
0.9968x = 9.96915
x = 9.96915/0.9968
x = 10.00%
∴ Recall that:
²⁵ Mg = x
²⁶ Mg = (21.01 - x)%
²⁵ Mg = 10.00%
²⁶ Mg = (21.01 - 10.00)%
²⁶ Mg = 11.0%
<span>"If they recover 10.5 it means you shall add with the limiting 10.8, giving you 21.3g out of 142 times 100, giving 15%, I believe."
By anonymous on openstudy.com
</span>