Question

A certain chemical reaction releases 362.kj of heat energy per mole of reactant consumed. Suppose some moles of the reactant are put into a calorimeter (a device for measuring heat flow). It takes 4.87j of heat energy to raise the temperature of this calorimeter by 5.5 C . Now the reaction is run until all the reactant is gone, and the temperature of the calorimeter is found to rise by . How would you calculate the number of moles of reactant that were consumed?
Set the math up. But don't do any of it. Just leave your answer as a math expression.

Also, be sure your answer includes all the correct unit symbols.

Answer 1

Answer:

The math is explained below. You need to include the amount by which the temperature of the calorimeter is found to rise by, which is missing on the quetion.

Explanation:

The amount that temperature of the calorimeter is found to rise is missing. So, I will do the math for a general amount X, and then will assume certain value to show the final calculation.

1) Data from the calorimeter:

• Raise of temperature of the calorimeter: X

• Ratio heat consumed: 4.87 J / 5.5°C (given)

• Energy absorbed by the calorimeter when its temperature increased X°:

              (4.87 J / 5.5°C ) × X

2) Data from the reaction:

• 362 kJ / mol of reactant

• number of moles of reactant: n

• Total amount of energy released by the reaction:

        362 kJ/mol × 1,000J/Kj × n = 362,000n J

3) By the law of conservation of the energy, assuming the calorimeter does not release energy to the surroundings, you equal the energy released by the reaction to the energy absorbed by the calorimeter when its temperature raised X°.

• 362,000 n =  (4.87 J / 5.5°C ) × X

• Solve for n: n = (4.87 / 5.5)X / 362,000

         n = 0.000002446 X

That means that for every degree the temperature of the calorimeter is found to increase, the number of moles of reactant consumed are 0.000002446 moles.

Example:

So, if the temperature of the calorimeter is raised by 100°C, the number of moles of reactant will be:

• n = 0.000002446 × 100 = 0.0002446 mol