Hello!
The half-life is the time of half-disintegration, it is the time in which half of the atoms of an isotope disintegrate.
We have the following data:
mo (initial mass) = 20 g
m (final mass after time T) = 5 g
x (number of periods elapsed) = ?
P (Half-life) = ? (in minutes)
T (Elapsed time for sample reduction) = 8 minutes
Let's find the number of periods elapsed (x), let us see:
Now, let's find the half-life (P) of the radioactive sample, let's see:
I Hope this helps, greetings ... DexteR! =)
First, we need to compute the mass of oxygen found in 100 grams of saltpeter:
mass of oxygen = 100 - (mass of potassium + mass of nitrogen)
= 100 - (38.67 + 13.86)
= 100 - 52.53
mass of oxygen in 100 grams saltpeter = 47.47 grams
Now, we can use cross multiplication to find the mass of oxygen in 328 grams saltpeter as follows:
mass of oxygen = (328 x 47.47) / 100 = 155.7016 grams
Answer:
Explanation:
Hello,
In this case, the molar enthalpy of reaction is obtained by dividing the involved energy by the reacting moles:
Thus, it is important to notice that the compound "uses" the energy, it means that it absorbs the energy, for that reason the sign is positive. Moreover, computing the result in kJ/mol we finally obtain:
Best regards.
