If the heat of combustion for a specific compound is −1160.0 kJ/mol and its molar mass is 86.47 g/mol, how many grams of this compound must you burn to release 541.20 kJ of heat?

40.34 g

Explanation:

First, we divide the heat to release by the heat of combustion to obtain the required moles of compound:

541.20 kJ/(1160.00 kJ/mol) = 0.4665 mol

So, we have to burn approximately 0.47 mol of the compound. We convert the moles to mass in grams by using the molar mass:

mass = molar mass x moles = 86.47 g/mol x 0.4665 mol = 40.34 g

Therefore, you must burn 40.34 grams of the compound to release 541.20 kJ of heat.

answer is: c. the experiment shows that the red substance experienced a chemical change.

this is chemical change (chemical reaction), because two new substances are formed (metalig liquid and gas), the atoms are rearranged and the reaction is followed by an energy change.

this is example of chemical decomposition.

chemical decomposition (analysis) is the separation of a single chemical compound into its two or more elemental parts or to simpler compounds.  

chemical decomposition is opposite of chemical synthesis.