A student pours 200 grams of methanol, a flammable substance into the sink. Another student causes the bad situation to get evern worse by dropping a lit match into the sink. The methanol burns completely with 300 grams of oxygen from the air.

What mass, in grams, is converted into energy?

Huh ?

This is a chemical reaction, not a nuclear explosion.

That's a much better answer than the one I gave two/three days ago. I'm still trying to find the limiting reagent.

LOL - well it sure had me flummoxed !

To calculate the mass converted into energy, we need to use the concept of stoichiometry and the balanced chemical equation for the combustion of methanol.

The balanced chemical equation for the combustion of methanol (CH3OH) is:

2CH3OH + 3O2 → 2CO2 + 4H2O

From the given information, we know that 200 grams of methanol completely reacts with 300 grams of oxygen (O2).

To find the mass of methanol converted into energy, we first need to determine the limiting reactant. This is the reactant that is completely consumed in a chemical reaction and determines the maximum amount of product that can be formed.

To find the limiting reactant, we need to compare the number of moles of methanol and oxygen. The molar mass of methanol (CH3OH) is 32 grams/mol, and the molar mass of oxygen (O2) is 32 grams/mol.

The number of moles of methanol can be calculated by dividing the mass of methanol (200 grams) by its molar mass (32 grams/mol):

Number of moles of methanol = 200 grams / 32 grams/mol = 6.25 moles.

The number of moles of oxygen can be calculated by dividing the mass of oxygen (300 grams) by its molar mass (32 grams/mol):

Number of moles of oxygen = 300 grams / 32 grams/mol = 9.375 moles.

From the balanced equation, we can see that the stoichiometric ratio between methanol and oxygen is 2:3. That means for every 2 moles of methanol, we need 3 moles of oxygen.

Comparing the number of moles of methanol (6.25 moles) and oxygen (9.375 moles), it is clear that methanol is the limiting reactant. This means that all of the methanol will be consumed in the reaction, and there will be excess oxygen remaining.

To find the mass of methanol converted into energy, we can use the stoichiometry:

From the balanced equation, we know that 2 moles of methanol react to produce energy. Therefore, for every 2 moles of methanol, a certain mass is converted into energy. We need to find this mass.

Using the molar mass of methanol (32 grams/mol), we know that 2 moles of methanol is equal to 2 moles × 32 grams/mol = 64 grams.

Therefore, 64 grams of methanol is converted into energy.

So, the mass of methanol converted into energy is 64 grams.