Answer:
a) The work done is 10.0777 kJ
b) The water's change in internal energy is -122.1973 kJ
Explanation:
Given data:
1 mol of liquid water
T₁ = temperature = 100.9°C
P = pressure = 1 atm
Endothermic reaction
T₂ = temperature = 100°C
1 mol of water vapor
VL = volume of liquid water = 18.8 mL = 0.0188 L
VG = volume of water vapor = 30.62 L
3.25 moles of liquid water vaporizes
Q = heat added to the system = -40.7 kJ
Questions: a) Calculate the work done on or by the system, W = ?
b) Calculate the water's change in internal energy, ΔU = ?
Heat for 3.25 moles:
The work done:
The change in internal energy:
Answer is none of the above
The answer is: the mass of 6.02 x 1023 representative particles of the element.
The base SI unit for molar mass is kg/mol, but chemist more use g/mol (gram per mole).
For example, molar mas of ammonia is 17.031 g/mol.
M(NH₃) = Ar(N) + 3 · Ar(H) · g/mol.
M(NH₃) = 14.007 + 3 · 1.008 · g/mol.
M(NH₃) = 17.031 g/mol.
The molar mass (M) is the mass of a given substance (in this example ammonia) divided by the amount of substance.
This reaction would produce salt and water- Sodium Sulphate and Water.
H₂SO₄ + 2NaOH → Na₂SO₄ + 2H₂O