What is the maximum kinetic energy of electrons ejected from barium when illuminated by white light, to 750 nm?

J

Explanation:

The complete statement is given as

What is the maximum kinetic energy of electrons ejected from barium (Wo = 2.48 eV) when illuminated by white light, 400 nm to 750 nm ?

= wavelength of the white light = 400 nm = 400 x 10⁻⁹ m

= speed of white light = 3 x 10⁸ ms⁻¹

Energy of the white light is given as

= Work function of barium = 2.48 eV = 2.48 x 1.6 x 10⁻¹⁹ J

= Maximum kinetic energy

Using photoelectric equation we have

  the grams     of oxygen gas   that can be produced     is 20.6   grams of o₂

calculation

2liclo₃ →   2 licl + 3 o₂

step 1:   find the moles of liclo₃

moles = mass÷ molar mass

from periodic table the molar mass of liclo₃ =6.9 +35.5   +(16 x3) =90.4 g/mol

moles=38.7 g÷90.4 g/mol=0.4281   moles

step 2:   use the   mole ratio   to calculate the moles of o2

from equation above, liclo₃: o₂   is 2: 3  

therefore the moles of   o₂=0.4281 moles x3/2 =0.6422   moles

step 3: find mass   of o₂

mass= moles x molar mass

from periodic table the   molar mass of   o₂ = 16 x2= 32 g/mol

mass=0.6422   moles   x   32 g/mol = 20.6 grams of o₂

true tan speed = ang vel x radius