Ethanol, c2h6o, is most often blended with gasoline - usually as a 10 percent mix - to create a fuel called gasohol. ethanol is a renewable resource and ethanol-blended fuels, like gasohol, appear to burn more efficiently in combustion engines. the heat of combustion of ethanol is 326.7 kcal/mol. the heat of combustion of octane, c8h18, is 1.308×103 kcal/mol. how much energy is released during the complete combustion of 406 grams of octane ? kcal assuming the same efficiency, would 406 grams of ethanol provide more, less, or the same amount of energy as 406 grams of octane?

Explanation:

Given,

The heat of combustion of octane = 1.308×10³ kcal/mol

It means that combustion of 1 mole of octane produces 1.308×10³ kcal of energy

Given mass = 406 g

Molar mass of octane = 114.23 g/mol

The formula for the calculation of moles is shown below:

Thus,

Moles of octane = 3.5542 moles

Combustion of 3.5542 moles produces 3.5542×1.308×10³ kcal of energy

Energy released from 406 grams of octane = 4.649×10³ kcal

Also given,

The heat of combustion of ethanol = 326.7 kcal/mol

It means that combustion of 1 mole of octane produces 326.7 kcal of energy

Given mass = 406 g

Molar mass of octane = 46.07 g/mol

The formula for the calculation of moles is shown below:

Thus,

Moles of octane = 8.8127 moles

Combustion of 8.8127 moles produces 8.8127×326.7 kcal of energy

Energy released from 406 grams of ethanol= 2879.11 kcal = 2.879×10³ kcal

It is less.

it can be observed without changing the identity of the object.

it depends on what substance you're talking about as well as many other factors. in quantum mechanics, the observation of particles affects the observers ability to measure certain properties. for example: you can know the velocity of a particle, but you can't know it's position; or you can know it's position, but not it's velocity. it's like trying to find out where a grain of sand is by throwing other grains of sand at it. once you find out where it is, it's been moved. it's also like trying to find an answer to the question of whether or not a tree falling in a forest makes a sound if nobody is there to hear it. paradoxically, the only way to find out is to be there and hear it.