CH3OH CO + 2H2 H = +90.7kJ
9. For the forward reaction, is heat being absorbed or released?
10. How much heat would be transferred if 45.0 g of CH3OH is decomposed?
11. What quantity of CH3OH decomposition would lead to an enthalpy change of 18.5 kJ
delta H is + which means heat is being absorbed.
1 mole CH3OH (32 g) absorbs 90.7 kJ heat. So 45 g CH3OH will absorb 90.7 x (45.0/32.0) = ??
Just use the above and plug in the numbers.
90.7 kJ x (grams CH3OH/32.0) = 18.5 kJ. Solve for grams CH3OH
To determine whether heat is being absorbed or released in the forward reaction, we need to look at the sign of the enthalpy change (∆H). In this case, the ∆H is given as +90.7 kJ.
If the ∆H is positive (+), it indicates that heat is being absorbed or taken in by the reaction.
If the ∆H is negative (-), it indicates that heat is being released or given off by the reaction.
In this case, since the ∆H is positive (+90.7 kJ), heat is being absorbed in the forward reaction.
To calculate the amount of heat transferred in question 10, we need to use the given equation and the molar mass of CH3OH.
1. Calculate the molar mass of CH3OH:
Carbon (C) – 12.01 g/mol
Hydrogen (H) – 1.01 g/mol
Oxygen (O) – 16.00 g/mol
Molar mass of CH3OH =
(1 × 12.01 g/mol) + (4 × 1.01 g/mol) + (1 × 16.00 g/mol) = 32.04 g/mol
2. Use the molar mass to calculate the number of moles of CH3OH:
Moles of CH3OH = mass (g) / molar mass (g/mol)
Moles of CH3OH = 45.0 g / 32.04 g/mol = 1.404 mol
3. Since the equation states that 1 mole of CH3OH decomposes to produce 1 mole of CO and 2 moles of H2 with a ∆H of +90.7 kJ, we use the stoichiometry to determine the amount of heat transferred.
1 mol CH3OH corresponds to 90.7 kJ of heat transferred.
Therefore, to calculate the heat transferred for 1.404 moles of CH3OH:
Heat transferred = (∆H * moles of CH3OH) / moles of CH3OH in the equation
Heat transferred = (+90.7 kJ * 1.404 mol) / 1 mol = 127.39 kJ
Thus, if 45.0 g of CH3OH is decomposed, the heat transferred would be 127.39 kJ.
To determine the quantity of CH3OH decomposition that would lead to an enthalpy change of 18.5 kJ, we can apply the same concept as above.
1 mol CH3OH corresponds to 90.7 kJ of heat transferred.
Therefore, to calculate the quantity of CH3OH decomposition for 18.5 kJ of heat transferred:
Quantity = (18.5 kJ * 1 mol) / 90.7 kJ
Quantity = 0.203 mol
Thus, a CH3OH decomposition of 0.203 mol would lead to an enthalpy change of 18.5 kJ.