Answer:
2.7 x 10^-19 J
Explanation:
The formula needed for this problem is
E = hν
where E = energy, h = Planck's constant = 6.626x10^-34 and ν is the frequency
c = λν
where c = speed of light = 3x10^8, and λ = wavelength
3x10^8 = 7.35x10^-7 . ν
ν = 4.08 x 10^14 Hz
E = 6.626x10^-34 . 4.08x10^14 = 2.7 x 10^-19 J
Answer:
wait did you tell up the answer?
Explanation:
Carbon, hydrogen, oxygen and nitrogen
First, we should get moles acetic acid = molarity * volume
=0.3 M * 0.5 L
= 0.15 mol
then, we should get moles acetate = molarity * volume
= 0.2 M * 0.5L
= 0.1 mol
then, we have to get moles of OH- which added:
moles OH- = molarity * volume
= 1 M * 0.02L
= 0.02 mol
when the reaction equation is:
CH3COOH + OH- → CH3COO- + H2O
moles acetic acid after adding OH- = (0.15-0.02)
= 0.13M
moles acetate after adding OH- = (0.1 + 0.02)
= 0.12 M
Total volume = 0.5 L + 0.02 L= 0.52 L
∴[acetic acid] = moles acetic acid after adding OH- / total volume
= 0.13mol / 0.52L
= 0.25 M
and [acetate ) = 0.12 mol / 0.52L
= 0.23 M
by using H-H equation we can get PH:
PH = Pka + ㏒[salt/acid]
when we have Ka = 1.8 x 10^-5
∴Pka = -㏒Ka
= -㏒ 1.8 x 10^-5
= 4.7
So by substitution:
∴ PH = 4.7 + ㏒[acetate/acetic acid]
= 4.7 + ㏒(0.23/0.25)
= 4.66
Answer:
35.453 atomic mass units
You can use Phet (Atomic masses, Elements and more) for Chemistry
