In calculating the relationship between the amount of heat added to a substance and the corresponding temperature change, the specific heat capacity is usually represented by which symbol? a) cb) qc) δtd) me) none of the above

A

Explanation:

The specific heat capacity can be defined as the amount of energy that is required to raise the temperature of 1kg of a body by exactly 1k.

When calculating the amount of heat required, we usually employ the use of the formula that relates the amount of heat, the mass of the body, the specific heat capacity and the temperature change. The amount of heat is represented by H, the mass of the body by m, the heat capacity by C while the temperature difference is represented by delta T

first, consult an activity series chart to determine if al is more reactive than fe. it is, so it will replace the fe. now, one can continue with the problem.

next, make sure you have a correctly balanced equation.

3feo + 2al ==> 3fe + al2o3

now, determine which reactant (feo or al) is in limiting supply.

moles feo present = 125 g x 1 mole/71.8 g = 1.74 moles

moles al present = 25.0 g x 1 mole/26.98 g = 0.927 moles

since from the balanced equation, it take 3 mol feo for every 2 mol al, al will be limiting.

you can determine this simply by dividing moles of each by their coefficient in the balanced equation. for example: 1.74/3 = 0.58 and 0.927/2 = 0.464. al is less, so it is limiting.

finally, using the stoichiometry in the balanced eq. determine mass of fe that can be produced from 0.927 moles of al.

0.927 moles al x 3 moles fe/2 moles al x 55.8 g/mole = 77.6 g