The vapors of some chemicals used in the chemistry laboratory, especially isocyanates, can react and bond the contact lens to the eye.
(FYI - the family of isocyanates include Superglue..I wouldn't want to have been the person who discovered this unfortunate reaction!)
The process that describes the transfer of heat through matter by activity of the molecules would be conduction. This type of heat transfer due to the motion of electrons and ions. within a body. As molecules collide with each energy is transferred and released which cause temperature to rise or drop.<span />
t1/2 = ln 2 / λ = 0.693 / λ
Where t1/2 is the half life of the element and λ is decay constant.
32 = 0.693 / λ
λ = 0.693 / 32 (1)
Nt = Nο eΛ(-λt) (2)
Where Nt is atoms at t time, λ is decay constant and t is the time taken.
t = 1.9 hours = 1.9 x 60 min
From (1) and (2),
Nt = Nο e⁻Λ(0.693/32)*1.9*60
Nt = 0.085Nο
Percentage = (Nt/Nο) x 100%
= (0.085Nο/Nο) x 100%
= 8.5%
Hence, Percentage of remaining atoms with the original sample is 8.5%
Answer:
0.14 moles of Fe₂O₃
Explanation:
Given parameters:
Number of moles of Fe = 0.27moles
Unknown:
Number of moles of Fe₂O₃ = ?
Solution:
To solve this problem, we are going to the work from the known specie to the unknown using their number of moles.
We first obtain the balanced equation of the reaction;
4Fe + 3O₂ → 2Fe₂O₃
The equation above is balanced;
4 moles of Fe produced 2 moles of Fe₂O₃
0.27 moles of Fe will produce 
= 0.14 moles of Fe₂O₃
