consider the following reaction:

2CH3OH(g) yields 2CH4(g) + O2(g) change in enthalpy= 252.8kJ

Calculate the amount of heat transferred when 26.0 g of {\rm CH_3OH} (g) is decomposed by this reaction at constant pressure.

I am assuming from the way the problem is stated that dH is +252.8 kJ for the reaction as written. Then

252.8 kJ x (26/2*molar mass CH3OH) = ?

For a given sample of CH3OH, the enthalpy change during the reaction is 82.6 kJ. How many grams of methane gas are produced?

2*16 x (82.6 kJ/252.8 kJ) = ? making the same assumption as above.

yes all of these parts are derived from the same problem

How many kilojoules of heat are released when 38.4 g of CH4 (g) reacts completely with O2 (g) to form CH3OH (g) at constant pressure?

beads?

To calculate the amount of heat transferred during this reaction, we can use the equation:

q = n * ΔH

where q is the amount of heat transferred, n is the number of moles of the substance undergoing the reaction, and ΔH is the change in enthalpy.

To determine the number of moles of CH3OH, we can use the molar mass of CH3OH. First, calculate the molar mass of CH3OH:

Molar mass of C = 12.01 g/mol
Molar mass of H = 1.01 g/mol
Molar mass of O = 16.00 g/mol

Molar mass of CH3OH = (4 * Molar mass of H) + Molar mass of C + (Molar mass of O) + (Molar mass of H)
= (4 * 1.01 g/mol) + 12.01 g/mol + 16.00 g/mol + (1.01 g/mol)
= 32.04 g/mol

Now, we can calculate the number of moles of CH3OH:

Number of moles = Mass / Molar mass
= 26.0 g / 32.04 g/mol

Once you've calculated the number of moles of CH3OH, multiply it by the change in enthalpy to obtain the amount of heat transferred:

q = (Number of moles of CH3OH) * ΔH
= (Number of moles of CH3OH) * 252.8 kJ

Substitute the value you obtained for the number of moles of CH3OH into the equation to get the final answer for the amount of heat transferred.

I've done two for you. Surely you don't need help on another one. They're all done the same way.