Answer:
The total energy change, ΔE, in kilojoules = -61.93 kJ
Explanation:
Relationship between ΔH, ΔE and work done is given by first law of thermodynamics.
ΔE = ΔH - PΔV
Where,
ΔH = Change in enthalpy
ΔE = Change in internal energy
PΔV = Work done
Given that,
ΔH = -75.0 kJ = -75000 J
P = 43.0 atm
ΔV = Final volume - initial volume
= (2.00 - 5.00) = -3.00 L
PΔV = 43 × (-3.00) = -129 L atm
1 L atm = 101.325 J
-129 L atm = 129 × 101.325 = -13071 J
So ,
ΔE = ΔH - PΔV
= (-75000 J) - ( -13071 J)
= -75000 J + 13071 J
= -61929 J
Total energy change, ΔE = -61.929 kJ
Molar mass:
Atomic mass O = 16.0 a.m.u
O₃ = 16.0 x 3 => 48.0 g/mol
Therefore:
1 mole O₃ --------------- 48.0 g
0.020 mole O₃ ---------- ??
0.020 x 48.0 / 1 =
0.96 / 1 => 0.96 g
hope this helps!
Answer:
The mole fraction of ethanol and water in the solution are 0.19 and 0.81 respectively.
Explanation:
The Molar Fraction is a way of measuring the concentration that expresses the proportion in which a substance is found with respect to the total moles of the solution, which are calculated by adding the moles of solute (s) and solvent.
It is calculated by dividing the number of moles of one of the components by the total number of moles of the solution.
The sum of all the molar fractions of the substances present in a solution is equal to 1.
So, the expression to calculate the mole fraction is:
Being the molar mass of the compounds:
- Ethanol 46
- Water 18
the number of moles that represent the mass quantities is calculated as:
- Moles of ethanol: 300 grams*
= 6.52 moles
- Moles of water: 500 grams*
= 27.78 moles
So the total moles in solution are 6.52 moles + 27.78 moles = 34.3 moles
The mole fraction of ethanol in the solution is calculated as:
The mole fraction of water in the solution is calculated as:
Then:
<u><em>The mole fraction of ethanol and water in the solution are 0.19 and 0.81 respectively.</em></u>
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Answer:
From the mass of Al reacted, how many moles are present? We don't have the mass of Al reacted
What is the mole ratio between Al and H2 in the balanced chemical reaction?
By stoichiometry, ratio between Al and H₂ is 3:2
What units are required on the temperature when doing calculations with gases? °K degrees
The value of R is 0.082 L.atm/mol.K
Explanation:
A chemical reaction for this can be this one:
2Al (s) + 6HCl (aq) → 2AlCl₃(aq) + 3H₂ (g)
Balanced
To get the moles which are present in the mass of Al reacted you must calculate:
Al Mass / Al molar mass = Al moles
The Ideal Gas equation is this one:
Pressure . Volume = n° moles . R (gases constant) . T°K
The temperature must be in K, because the units of R
We usually use R = 0.082 L.atm/mol.K
