Answer is: there is 1,77·10²³ molecules of CH₂Cl₂.
m(CH₂Cl₂) = 25 g.
n(CH₂Cl₂) = m(CH₂Cl₂) ÷ M(CH₂Cl₂).
n(CH₂Cl₂) = 25 g ÷ 85 g/mol.
n(CH₂Cl₂) = 0,294 mol.
N(CH₂Cl₂) = n(CH₂Cl₂) · Na.
N(CH₂Cl₂) = 0,294 mol · 6,023 1/mol.
N(CH₂Cl₂) = 1,77·10²³.
n - amount of substance.
Na - Avogadro number.
Mendeleevs Periodic Table
Answer:
The wavelength the student should use is 700 nm.
Explanation:
Attached below you can find the diagram I found for this question elsewhere.
Because the idea is to minimize the interference of the Co⁺²(aq) species, we should <u>choose a wavelength in which its absorbance is minimum</u>.
At 400 nm Co⁺²(aq) shows no absorbance, however neither does Cu⁺²(aq). While at 700 nm Co⁺²(aq) shows no absorbance and Cu⁺²(aq) does.
Answer:
mL
Explanation:
Atmospheres (atn), Torr, and mm of Hg are all units of pressure but mL is a unit of volume, not pressure.
Kc= (nh4)
--------
(nh3) + (h2o)