write the equation for the reaction
that is 6 F2 +P4 =4 PF3
find the theoretical mass that is
let the theoretical yield be represented by y
theoretical yield = 78.1/100 = 120/y
y= 153.6 grams
find the number of moles of PF3
moles = mass/molar mass
= 153.6/87.97 =1.746 moles
by use of mole ratio between F2 :PF3 which is 6:4 the moles of F2 is therefore= 1.746 x 6/4 = 2.62 moles
mass = moles x molar mass
= 1.746 moles x38 g/mol = 99.6 grams
Answer:
Explanation:
Work function of potassium = 2.29 eV = 3.67 X 10⁻¹⁹ J
So the minimum energy of photon must be equal to 3.67 X 10⁻¹⁹ J .
energy of photon of wavelength λ = hc / λ
where h = 6.67 x 10⁻³⁴
c = 3 x 10⁸
Putting the values in the equation above
6.67 x 10⁻³⁴ x 3 x 10⁸ / λ = 3.67 X 10⁻¹⁹
λ = 6.67 x 10⁻³⁴ x 3 x 10⁸ / 3.67 X 10⁻¹⁹
= 5.452 x 10⁻⁷
= 5452 x 10⁻¹⁰ m
= 5452 A .
Potassium outermost electron occupy "4s" orbital
Answer:
The 197Au isotope has 79 protons, 79 electrons and 118 neutrons
Explanation:
Step 1: The isotope = 197Au
Step 2: Calculate neutrons, electrons and protons
197 = Number of protons + number of neutrons
Isotopes always have the same proton number ( is the same as the atomic number). For Gold (Au) is this 79.
The number of electrons is equal to the number of protons in a neutral atom. Since we have 79 protons, there are also 79 electrons.
All isotopes of Au have a different number of neutrons.
The number of neutrons = 197 -79 = 118 neutrons
The 197Au isotope has 79 protons, 79 electrons and 118 neutrons
