Answer:
64.0 g/mol.
Explanation:
- Thomas Graham found that, at a constant temperature and pressure the rates of effusion of various gases are inversely proportional to the square root of their masses.
<em>∨ ∝ 1/√M.</em>
where, ∨ is the rate of diffusion of the gas.
M is the molar mass of the gas.
<em>∨₁/∨₂ = √(M₂/M₁)</em>
∨₁ is the rate of effusion of the unknown gas.
∨₂ is the rate of effusion of He gas.
M₁ is the molar mass of the unknown gas.
M₂ is the molar mass of He gas (M₂ = 4.0 g/mol).
<em>∨₁/∨₂ = 0.25.</em>
∵ ∨₁/∨₂ = √(M₂/M₁)
∴ (0.25) =√(4.0 g/mol)/(M₁)
<u><em>By squaring the both sides:</em></u>
∴ (0.25)² = (4.0 g/mol)/(M₁)
∴ M₁ = (4.0 g/mol)/(0.25)² = 64.0 g/mol.
Answer:
Helium and Ethlyene Oxide. Your answer is MASS.
Explanation:
Diffusion is faster at higher temperatures because the gas molecules have greater kinetic energy. effusion refers to the movement of gas particles through a small hole. Graham's law state's that the effusion rate of a gas is inversely proportional to the square root of the mass of its particles.
The formula for dimethyl mercury is. HgC2H6 = (2x12) + (6x1) + (1x200.6) = 230.6
So the molar mass of dimethyl mercury is 230.6 g/mol.
Number of moles in 4.2g of dimethymercury = 4.2/ 230.6 = 0.0182 moles.
1 moles of dimethymercury contains 6.02 * 10^23
Hence 0.0182 moles contains X
X = 0.0182 * 6.02 * 10^23 = 0.10952 * 10^23 = 1.0952 * 10^22.
When dT = Kf * molality * i
= Kf*m*i
and when molality = (no of moles of solute) / Kg of solvent
= 2.5g /250g x 1 mol /85 g x1000g/kg
=0.1176 molal
and Kf for water = - 1.86 and dT = -0.255
by substitution
0.255 = 1.86* 0.1176 * i
∴ i = 1.166
when the degree of dissociation formula is: when n=2 and i = 1.166
a= i-1/n-1 = (1.166-1)/(2-1) = 0.359 by substitution by a and c(molality) in K formula
∴K = Ca^2/(1-a)
= (0.1176 * 0.359)^2 / (1-0.359)
= 2.8x10^-3
Answer:
A (Hypothesis) is scientific knowledge published through direct observation and remains constant scientific knowledge can change when scientists (generate hypothesis)
