Yes. Percent yield shows how efficient one's method is. If his isolated caffeine proved to be at only 1.5%, compared to least 50% as in many of the previous experiments, the student should be very concerned as it shows that something caused the yield to sharply drop.
Answer:
Therefore it will take 7.66 hours for 80% of the lead decay.
Explanation:
The differential equation for decay is


Integrating both sides
ln A= kt+c₁

[
]
The initial condition is A(0)= A₀,


.........(1)
Given that the
has half life of 3.3 hours.
For half life
putting this in equation (1)

[taking ln both sides,
]

⇒k= - 0.21
Now A₀= 1 gram, 80%=0.8
and A= (1-0.8)A₀ = (0.2×1) gram = 0.2 gram
Now putting the value of k,A and A₀in the equation (1)




⇒ t≈7.66
Therefore it will take 7.66 hours for 80% of the lead decay.
Answer:
The air will reach a higher final temperature because its specific heat is lower.
Explanation:
Answer:
Sodium Chloride has Ionic bond while Hydrogen Chloride has covalent bond.
Explanation:
Na has 11 electrons (2, 8, 1) and need to give away 1 electron to be stable
Cl has 17 electrons ( 2, 8, 7) and needs 1 electron to be stable.
Na transfers 1 electron to CL to form Ionic bond.
While
Hydrogen has 1 electron and shares with Chlorine to be stable.
Covalent bond involves sharing.