Answer:
E = hf
E = hc/lamda
where E-energy,
h-planck's constant (6.62 x 10^-34 Js)
f- frequency ( f = c/lamda)
c-velocity of light ( 3 x 10^8 m/s)
lamda- wavelength
you can this formula to solve all the 4 questions.
The molarity of a solution is the number of moles of a substance in one liter of that substance.
The molar mass of ammonium sulfate (NH4)2SO4 is 132.14 grams/mole
Calculate the moles of ammonium sulfate:
(4.50 grams)/(132.14 grams/mole) = 0.0341 moles of ammonium sulfate
convert mL to Liters 250. mL becomes 0.250 liters
Take the number of moles over the number of liters
0.0341 moles / 0.250 liters = 0.136 molar or 0.136M = molarity of the solution
Answer:If we have [H+][OH-]= Kw = 1.0 x 10^-14
Then [H+]= Kw/ [OH-]= 1.0x 10^-14/ 1 x 10^-11 =1 x 10^-3 mol/L
And here is the solution - as you can see it is an acidic one :
pH = - log [H+]= - log 1 x 10^-3 = 3 < 7
Explanation:
