Answer:
24.03 J/mol.ºC
Explanation:
For a calorimeter, the heat lost must be equal to the heat gained from water plus the heat gained from calorimeter, which has the same initial temperature as the water.
-Qal = Qw + Qc (minus signal represents that the heat is lost)
-mal*Cal*ΔTal = mw*Cw*ΔTw + Cc*ΔTc
Where m is the mass, C is the specific heat, ΔT is the temperature variation, al is from aluminum. w from water and c from the calorimeter. Cw = 4.186 J/gºC
-25.5*Cal*(22.7 - 100) = 99.0*4.186*(22.7 - 18.6) + 14.2*(22.7 - 18.6)
1971.15Cal = 1699.10 + 58.22
1971.15Cal = 1757.32
Cal = 0.89 J/g.ºC
The molar mass of Al is 27 g/mol
Cal = 0.89 J/g.ºC * 27 g/mol
Cal = 24.03 J/mol.ºC
We calculate first for the number of moles of gases in the sample through the ideal gas equation.
n = PV/RT
n = (725 mmHg/760 mmHg/atm)(0.255 L) / (0.0821 L.atm/mol.K)(65 + 273.15)
n = 8.76 x 10^-3 mol
Then, we calculate for the mol N2 using the ratio of the pressure.
n N2 = (8.76 x 10^-3 mols)(231 mmHg/725 mmHg)
n N2 = 2.79 x 10^-3 moles
Then, multiply the value with the molar mass of N2 which is 28 grams per mol giving us the answer of 0.078 grams.
Wegener's idea that pangaea drifted into a continents
Molarity is calculated using the following equation:
number of moles solute/ number of litres of solvent.
Number of moles = 0.2 moles (given)
1 litre = 1000 ml
Therefore, 200 ml = 0.2 litres
Using the previously mentioned equation, we can calculate molarity as follows:
Molarity = 0.2/0.2 = 1
