Is nitrogen gas a pure substance or a mixture
1 answer:
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Half-life is the time taken for the concentration of the substance to reduce by 50%. The original sample of strontium had a mass of 1.6 gms. Thus, option d is correct.
<h3>What is half-life?</h3>The half-life of any radioactive substance is the time period at which the concentration will get reduced to half the initial amount. The initial mass of Sr-90 is calculated as,
Given,
Quantity of the remaining substance N (t) = 0.40 gm
Initial radioactive substance quantity =?
Time duration (t) = 56 years
Half-life = 28 years
Substituting values above:
= 1.6 gm
Therefore, option d. the initial mass of Sr is 1.6 gm.
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Answer:
44.28 grams.
Explanation:
Let us write the balanced reaction:
As per balanced equation, six moles of fluorine gas will give four moles of PF₃.
The mass of PF₃ required = 120 g
The molar mass of PF₃ = 88g/mol
Moles of PF₃ required =
The moles of fluorine gas required =
the mass of fluorine gas required = moles X molar mass = 0.91x38 = 34.58g
Now this much mass will be required if the reaction is of 100% yield
But as given that the yield of reaction is only 78.1%
The mass of fluorine required =