Cl is stable as a diatomic molecule where the 2 Cl atoms are held together by a covalent bond
molar mass of the diatomic molecule is 70.9 g/mol
therefore 70.9 g of Cl₂ is - 1 mol
then 140 g of Cl₂ is - 1/70.9 x 140 = 1.97 mol
there are 1.97 mol of Cl₂ present
For this question, lets apply Avagadro's law
when Pressure and temperature are constant, the volume occupied is directly proportional to the number of moles of gases.

where V-volume, n-number of moles and k - constant
Therefore at 2 instances

where V1 and n1 are for 1st instance
and V2 and n2 are for 2nd instance
therefore

V1 = 2.4 L
n1 = 3.7 mol
n2 = 3.7 + 1.6 = 5.3 mol
since more He moles are added at the 2nd instance its the sum of the moles.
V2 needs to be calculated

V2 = 2.4 x 5.3 / 3.7
= 3.4 L
Answer is 1st option 3.4 L
Answer:
λ = 2.38 × 10^(-7) m
Explanation:
We are given the work function for palladium as 503.7 kJ/mol.
Now let's convert this to KJ/electron.
We know from avogadro's number that;
1 mole of electron = 6.022 × 10^(23) electrons
Thus,
503.7 kJ/mol = 503.7 × 1/(6.022 × 10^(23)) = 8.364 × 10^(-22) KJ/electron = 8.364 × 10^(-19) J/electron
Formula for energy of a photon is;
E = hv
Where;
h is Planck's constant = 6.626 × 10^(-34) J.s
v is velocity
Now, v = c/λ
Where;
c is speed of light = 3 × 10^(8) m/s
λ is wavelength of light.
Thus;
E = hc/λ
Making λ the subject, we have;
λ = hc/E
λ = (6.626 × 10^(-34) × 3 × 10^(8))/(8.364 × 10^(-19))
λ = 2.38 × 10^(-7) m