The law is approximately valid for real gases at sufficiently low pressures and high temperatures. The specific number of molecules in one gram-mole of a substance, defined as the molecular weight in grams, is 6.02214076 × 1023, a quantity called Avogadro's number, or the Avogadro constant.
Answer:
12.50g
Explanation:
T½ = 2.5years
No = 100g
N = ?
Time (T) = 7.5 years
To solve this question, we'll have to find the disintegration constant λ first
T½ = In2 / λ
T½ = 0.693 / λ
λ = 0.693 / 2.5
λ = 0.2772
In(N/No) = -λt
N = No* e^-λt
N = 100 * e^-(0.2772*7.5)
N = 100*e^-2.079
N = 100 * 0.125
N = 12.50g
The sample remaining after 7.5 years is 12.50g
Answer: 6 moles
Take a look at the balanced chemical equation for this synthesis reaction
N 2(g] + 3 H 2(g] → 2 NH 3(g]
Notice that you have a 1:3 mole ratio between nitrogen gas and hydrogen gas. This means that, regardless of how many moles of nitrogen gas you have, the reaction will always consume twice as many moles of hydrogen gas.
So, if you have 2 moles of nitrogen taking part in the reaction, you will need
2 moles N 2 ⋅ 3 moles H 2 /1 mole N 2 = 6 moles H 2
Accidental fires, explosions, and chemical and gas leaks are common at refineries. Such accidents cause higher than usual amounts of pollution, which may result in more acute exposure to pollutants and greater health impacts.
