Answer:
trial 2: 0.74
trial 3: 5.19
I think but the equation for sloving percent error is:
(true value - determined value)/true value * 100
Explanation:
The limiting reactant when 5.6 moles of aluminium react with 6.2 moles of water is
water( H2O)
<u><em>Explanation</em></u>
The balanced equation is as below
2 Al +3 H2O → Al2O3 +3 H2
The mole ratio of Al :Al2O3 is 2:1 therefore the moles of Al2O3
= 5.6 x1/2 = 2.8 moles
The mole ratio of H2O: Al2O3 is 3:1 therefore the moles of Al2O3 produced
= 6.2 x1/3= 2.067 moles
since H2O yield less amount of Al2O3 , H2O is the limiting reagent.
Based on the bond energies given, the enthalpy change for the reaction of is -33 kJ and the reaction is exothermic.
<h3>What is the change in bond energy of a reaction?</h3>
The change in bond energy of a reaction is calculated using the formula below:
- change in bond energy = sum of energies of bonds broken - sum of energies of bonds formed
A reaction is exothermic if the change in bond energy is negative.
A reaction is endothermic if the change in bond energy is positive.
Given the bond enery values above:
sum of energies of bonds broken = 4 × C-H + Br-Br
sum of energies of bonds broken = 4 × 413 + 193 = 1845 kJ
sum of energies of bonds formed = 3 × C-H + C-Br + H-Br
sum of energies of bonds formed = 3 × 413 + 276 + 363 = 1878 kJ
Thus;
change in bond energy = 1845 - 1878 = -33 kJ
- The reaction is exothermic because the change in bond energy is negative.
Therefore, the enthalpy change for the reaction of is -33 kJ and the reaction is exothermic.
Learn more about enthalpy change at: brainly.com/question/11628413
