Data:
p = 1 atm
V = 10 m * 8 m * 5 m = 400 m^3 = 400,000 liter
To = 0 + 273.15K = 273.15K
Tf = 20 + 273.15K = 293.15K
No - Nf =?
2) Formula
pV = NRT => N = pV / (RT)
3) solution
No = pV / (RTo)
Nf = pV / (RTf)
=> No - Nf = [pv / R] [ 1 / To - 1 / Tf ]
=> No - Nf = [1atm*400,000liter / 0.0821 atm*liter/K*mol ] [ 1 / 273.15 - 1 / 293.15]
No - Nf = 1216.9 moles ≈ 1217 moles
Answer: 1217 moles
5 moles.
think about the ratio of moles of iron oxide (Fe2O3) and iron (Fe) in that balanced chemical equation, which is 1:2, respectively. if there are 10 moles of Fe, you would divide that by 2 to get the number of moles of Fe2O3.
Answer:
9.39 × 10²² molecules
Explanation:
We can find the moles of gases (n) using the ideal gas equation.
P . V = n . R . T
where,
P is the pressure (standard pressure = 1 atm)
V is the volume
R is the ideal gas constant
T is the absolute temperature (standard temperature = 273.15 K)
There are 6.02 × 10²³ molecules in 1 mol (Avogadro's number). Then,
Answer:
The new volume of the gas is 276.45 mL.
Explanation:
Charles's law indicates that for a given sum of gas at constant pressure, as the temperature increases, the volume of the gas increases, and as the temperature decreases, the volume of the gas decreases.
Charles's law is a law that mathematically says that when the amount of gas and pressure are kept constant, the quotient that exists between the volume and the temperature will always have the same value:
Analyzing an initial state 1 and a final state 2, it is satisfied:
In this case:
- V1= 250 mL
- T1= 293 K
- V2= ?
- T2= 324 K
Replacing:
Solving:
V2= 276.45 mL
<em><u>The new volume of the gas is 276.45 mL.</u></em>
Answer is: D. Na2SO4.
b(solution) = 0.500 mol ÷ 2.0 L.
b(solution) = 0.250 mol/L.
b(solution) = 0.250 m; molality of the solutions.
ΔT = Kf · b(solution) · i.
Kf - the freezing point depression constant.
i - Van 't Hoff factor.
Dissociation of sodium sulfate in water: Na₂SO₄(aq) → 2Na⁺(aq) + SO₄²⁻(aq).
Sodium sulfate dissociates on sodium cations and sulfate anion, sodium sulfate has approximately i = 3.
Sodium chloride (NaCl) and potassium iodide (KI) have Van 't Hoff factor approximately i = 2.
Carbon dioxide (CO₂) has covalent bonds (i = 1, do not dissociate on ions).
Because molality and the freezing point depression constant are constant, greatest freezing point lowering is solution with highest Van 't Hoff factor.
