In a calorimeter experiment done at constant pressure in which all the heat from a chemical reaction was absorbed by the surrounding water bath, the temperature of the water went up by 2.31 K. If the size of the water bath was 200 g, what was the amount of heat transferred to the water? If the chemical reaction was
CH4(g) + 2O2(g) --> CO2(g) + 2H2O(l)
and 2.17x1-^-3 moles of CH4 were burned, what is DH for the reaction?
I got 1.00J
Off hand I wouldn't think so.
q = mass H2O x specific heat H2O x delta T = ?,I think the question is stated improperly. This is the dH for the reaction as shown. What the problem wants, I think, is dH for the reaction/mol. That is
Then q/mol CH4 = dH for the reaction. I get something like 890 kJ/mol.
To calculate the amount of heat transferred to the water, you can use the formula:
q = mcΔT
Where:
q = heat transferred
m = mass of the water bath
c = specific heat capacity of water
ΔT = change in temperature
Given:
m = 200 g
c = 4.18 J/g°C (specific heat capacity of water)
ΔT = 2.31 K
Substituting the values into the formula:
q = (200 g)(4.18 J/g°C)(2.31 K)
q = 1931.64 J
Therefore, the amount of heat transferred to the water is 1931.64 J.
To calculate ΔH for the reaction, you need to use the equation:
ΔH = q/n
Where:
ΔH = enthalpy change
q = heat transferred
n = number of moles of reactant (CH4)
Given:
q = 1931.64 J
n = 2.17x10^-3 moles
Substituting the values into the equation:
ΔH = 1931.64 J / 2.17x10^-3 moles
ΔH ≈ 890,991.24 J/mol
Therefore, ΔH for the reaction is approximately 890,991.24 J/mol.
To find the amount of heat transferred to the water, you can use the equation:
q = mcΔT
where:
q is the amount of heat transferred,
m is the mass of the water bath,
c is the specific heat capacity of water, and
ΔT is the change in temperature.
Given that the mass of the water bath (m) is 200 g, the change in temperature (ΔT) is 2.31 K, and the specific heat capacity of water (c) is approximately 4.18 J/g·K, you can calculate the amount of heat transferred (q).
q = (200 g) × (4.18 J/g·K) × (2.31 K)
q = 1932.24 J
Therefore, the amount of heat transferred to the water is approximately 1932.24 J.
To determine the enthalpy change (ΔH) for the reaction, you need to calculate the amount of heat per mole of CH4 burned. This can be done using the equation:
ΔH = q / n
where:
ΔH is the enthalpy change,
q is the amount of heat transferred,
and n is the number of moles of CH4 burned.
Given that the number of moles of CH4 burned (n) is 2.17 × 10^-3 moles and the amount of heat transferred (q) is 1932.24 J, you can calculate the enthalpy change (ΔH).
ΔH = (1932.24 J) / (2.17 × 10^-3 moles)
ΔH = 891,429.34 J/mol
Therefore, the enthalpy change (ΔH) for the reaction is approximately 891,429.34 J/mol, or 891.43 kJ/mol.