It should be equal to the mass of the carbon plus the mass of the oxygen. This is because of the conservation of mass law. Mass is never created or destroyed only conserved. Hope this helped
The answer is (A).
Hope this helps :).
Use the ideal gas law: PV = nRT, and solve for T,
T = PV/nR.
We should convert any of our parameters to units that would be easy to use with a known R value. One option would be to have the pressure in atm, volume in L, and convert the mass of the hydrogen gas to moles:
P = 1.2 atm
V = 750 mL = 0.750 L
n = (0.30 g H2)/(2.0159 g/mol) = 0.1488 mol H2
R = 0.0821 L•atm/mol•K.
Solving for T,
T = (1.2 atm)(0.750 L)/(0.1488 mol H2)(0.0821 L•atm/mol•K) = 73.671 K.
If you opt to leave your temperature in Kelvin, I would go with 74 K, as that has two significant figures like the rest of the values.
If you opt to go with Celsius, then the answer would be a bit awkward if you had to follow two sig figs: 73.671 - 273.15 = -199.49 ≈ -2.0 × 10² °C.
Pick your poison, I suppose.
