3.

Chemistry

1 answer:

Vsevolod [243]3 years ago

3 0

Answer:

2 half-lives=0.8

6 half-lives= 0.05

Explanation

Half-lives are constant and always decrease by half, implying that the concentration decreases by half at a consistent rate.

3.2/2= 1.6/2= 0.8 is two half-lives

3.2/2= 1.6/2= 0.8/2= 0.4/2= 0.2/2= 0.1/2=0.05 is six half-lives

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We know that:
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Now, from the general law of gases:
PV = nRT
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P is the pressure = 500 torr = 0.65 atm
V is the volume
n is the number of moles
R is the gas constant = 0.082
T is the temperature = 300 k
We will just rearrange this equation as follows:
P = nRT / V
Then we will substitute n with its equivalent equation mentioned at the beginning:
P = (mass x R x T) / (volume x molar mass) ......> equation I
Now, we know that:
density = mass / volume
We will substitute (mass/volume) in equation I with density as follows:
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molecular mass of nitrogen = 14 grams
Therefore:
molar mass of hydrogen = 2 x 1 = 2 grams
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We can assume that the number of moles of of each element is y.
We can thus build up the following equation:
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