The answer:
all that we search for is the number of mole of HCl and the number of mole of C2H6O
M(HCl) = 5.5g/ mole of HCl , so mole of HCl = 5.5/M(HCl), where M(HCl) is the molar mass.
M(HCl) = 1+ 36.5= 37.5
moles of HCl = 5.5/37.5=0.14
M(C2H6O) = 200g / moles of C2H6O, so moles of C2H6O=200g / M(C2H6O)
M(C2H6O)= 2x12+ 6 + 16=46,
moles of C2H6O=200g / 46 =<span>4.35 </span><span> moles
</span>
the sum of the moles is 0.14 + <span>4.35 </span> = 4.501 moles
finally, <span>The mole fraction of hcl in a solution prepared by dissolving 5.5 g of hcl in 200 g of c2h6o is 0.031
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because it can be found by 0.14 / 4.501= 0.031
The radioactive decay obeys first order kinetics
the rate law expression for radioactive decay is
![ln\frac{[A_{0}]}{[A_{t}]}=kt](https://tex.z-dn.net/?f=ln%5Cfrac%7B%5BA_%7B0%7D%5D%7D%7B%5BA_%7Bt%7D%5D%7D%3Dkt)
Where
A0 = initial concentration
At = concentration after time "t"
t = time
k = rate constant
For first order reaction the relation between rate constant and half life is:

Let us calculate k
k = 0.693 / 72 = 0.009625 years⁻¹
Given
At = 0.25 A0

time = 144 years
So after 144 years the sample contains 25% parent isotope and 75% daughter isotopes**
Simply two half lives
Answer:
I think the answer is 4) 41
Explanation:
APE= atomic number, proton and the electrons are the same number
MAN= mass = atomic number - neutrons
121 - 80 = 41
i haven't done this in a while so hope this helps :)
Answer:
It will be denatured.
Explanation:
Salivary amylase works best at pH 6.8.
At pH 2.5, its activity will decrease enormously as it becomes denatured by the high acidity of the stomach contents.