Answer:
0.57 atm
Explanation:
When a a reaction is first order, we have from calculus the following relation:
ln[A]t/[A]₀ = - kt
where [A]t is the concentration of A ( phosphine in this case ) after a time, t
[A]₀ is the initial concentration of A
k is the rate constant, and
t is the time
We also know that for a first order reaction
k = 0.693/ t 1/2
wnere t 1/2 is the half-life.
This equation is derived for the case when A]t/= 1/2 x [A]₀ which occurs at the half-life.
Thus, lets first find k from the half life time, and then solve for t = 70.5 s
k = 0.693 / 35.0 s = 0.0198 s⁻¹
ln [ PH₃ ]t / [ PH₃]₀ = - kt
from the ideal gas law we know pV = nRT, so the volumes cancel:
ln (pPH₃ )t / p(PH₃)₀ = - kt
taking inverse log to both sides of the equation:
(pPH₃ )t / p(PH₃)₀ = - kt
thus:
(pPH₃ )t = 2.29 atm x e^(- 0.0198 s⁻¹ x 70.5 s ) = 0.57 atm
Hold on give me a moment to answer this for you.
Answer:
YesEdit: sorry I thought you asked "Is Sodium a metal?" It is a metal because it is on the left side of the periodic table and it has metallic properties such as:
It is malleable
Shiny when polished
Forms positive ions when it reacts
And has a high boiling pointpoint
Explanation:
Well, when an atom attains a stable valence electron, it means that the outer electrons are complete and so cannot attain any more electrons. For the first shell, it is complete when it has 2 electrons, the second shell is complete when it has 8 electrons, all the other shells also have a particular number when complete. Anyway, i believe the answer is HYDROGEN because when HYDROGEN combines with another atom of HYDROGEN, the outer shell is completed. This is because HYDROGEN has only 1 electron. If the two HYDROGENS, which both have 1 electron combine, they make the electrons 2, which is complete for the first shell, HYDROGEN ends in the first shell. Since the electrons become 2, the shell is at stable valence. In all the other options, this happens;
NEON- It has 10 electrons, 2 in the first shell and 8 in the second. So the the shells are already complete, so it can't bond with any thing, which is completely against the question.
RADON- Radon has 86 electrons.
HELIUM- Helium has 2 electrons, so the shell is already full, and cannot bond, so it goes against the question. The question says BY BONDING.
So the answer is definitely 4) HYDROGEN
Hope i helped. Have a nice day, by the way, i'm very sure it's hydrogen.
B is the correct answer 9.0122
