Answer:
180 mg
Explanation:
For a first-order reaction, we can calculate the amount of aspirine (A) at a certain time (t) using the following expression.
where,
k: rate constant
A₀: initial amount
If we know the half-life (
) we can calculate the rate constant.
When t = 4 h and A₀ = 400 mg, A is:
density= mass/volume
we need the volume of the metal to find the density, in which case the answer would be 64.2/volume=density
Peroxide is the chemical responsible for opening the hair cuticle
The delta H of -484 kJ is the heat given off when 2 moles of H2 react with 1 mole of O2 to make 2 moles of H2O. You don't have anywhere near that much reactants, only 1/4 as much
<span>actual delta H = 0.34 moles H2 x (-484 kJ / 2 moles H2) = 823 kJ </span>
<span>delta E = delta H - PdeltaV = 823 kJ - 0.41 kJ = 822 kJ</span>
