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:
A lithosphere is the rigid, outermost shell of a terrestrial-type planet, or natural satellite, that is defined by its rigid mechanical properties.
Explanation:
the rigid outer part of the earth, consisting of the crust and upper mantle.
Round 89 to 90 then divide by 4. so its 24.
Answer:
1. Qsol = -5.87 kJ
2. ΔHrn = 18.4 kJ/mol
Explanation:
According to the law of conservation of energy, the sum of the heat absorbed by the reaction and the heat released by the solution is zero.
Qrn + Qsol = 0
Qrn = -Qsol
We can calculate the heat released by the solution using the following expression.
Qsol = c . m . ΔT
where,
c: specific heat capacity of the solution
m: mass of the solution
ΔT: change in the temperature
Qsol = (4.184 J/g.°C) . (243g + 32.3g) . (17.90°C-23.00°C) = -5.87 × 10³ J = -5.87 kJ
The heat absorbed by the reaction is:
Qrn = -Qsol = 5.87 kJ
In the balanced equation, we have 1 mole of KNO₃. Given we are in a constant-pressure calorimeter, the enthalpy of reaction (per mole of KNO₃) is: