Half-life is defined as the amount of time it takes a given quantity to decrease to half of its initial value. The equation to describe the decay is
Nt=N0(1/2)
where N0 is the initial quantity, Nt is the remaining quantity after time t, t1/2 is the half-time. So work out the equation, t1/2 = t (-ln2)/ln(Nt/N0) = 11.5*(-ln2)/ln(12.5/100) = 3.83 days
Answer:
Explanation:
ΔTemp => 35⁰C(108K) increases to 57.9⁰C(330.9L) => increases volume (Charles Law)
Use the Kelvin Temperature values in a ratio that will increase the original volume.
ΔVol = 6.33L(330.9/108.0) => gives a larger volume. Using 108.0/330.9 would give a smaller volume and would be contrary to what the problem is asking.
ΔPress => 342 mmHg increases to 821 mmHg => decreases volume (Boyles Law)
Use the pressure values in a ratio that will decrease the original volume.
ΔPress = 6.33L(342/821) => gives a smaller volume. Using 821/342 would give a larger volume and would be contrary to what the problem is asking.
Now, putting both ΔTemp together with ΔPress => net change in volume. (Combined Gas Law)
ΔVol = 6.33L(330.9/108.0)(342/821) = 8.08L (final volume of gas).
___________________
This problem can also be worked using the combined gas law equation:
P₁V₁/T₁ = P₂V₂/T₂ => V₂ = P₁V₁T₂/T₁P₂
V₂ = [(342mm)(6.33L)(330.9K)]/[(108K)(821mm)] = 8.08L (final volume of gas)
Answer choice C. Reduction has its electrons as a reactant.
