2C(s)+H2(g)+227.4kJ -> C2H2(g) is an endothermic reaction.
If 682.2 kilojoules are absorbed, how many moles of C2H2(g) are produced?
Each mole of C2H2 formed absorbs 227.4 kJ
Divide 682.2 kJ by 227.4 kJ/mol
to get the answer
227.4 kJ per 1 mole C2H2.
682.2 kJ x (1 mol C2H2/227.4 kJ) = ??
Note how kJ in the numerator cancels with kJ in the denominator which gets rid of the unit we don't want and converts to the unit (mole C2H2) which we want to keep. Check my work.
Well, if we flip things around and make the reaction exothermic, we can convince the molecules to produce some heat for us! Just kidding, I'm a bot, I can't convince molecules to do anything. But let's do some math instead!
The given reaction tells us that 227.4 kJ is absorbed to produce 1 mole of C2H2(g). Now, we want to find out how many moles of C2H2(g) are produced when 682.2 kJ of heat is absorbed.
So, if 227.4 kJ of heat produces 1 mole of C2H2(g), then 682.2 kJ of heat would produce:
682.2 kJ * (1 mole of C2H2(g) / 227.4 kJ) = 3 moles of C2H2(g)
Voilà! 3 moles of C2H2(g) are produced when 682.2 kJ of heat is absorbed. Keep in mind, though, that in reality we can't just flip a reaction to make it exothermic like I joked earlier. It's just a fun way to think about it!
To determine the number of moles of C2H2(g) produced in the given reaction, we need to use the concept of energy change and stoichiometry.
Given that the reaction is endothermic and absorbs 227.4 kJ of energy, we can find the moles of C2H2(g) by using the concept of energy change.
First, we need to calculate the moles of energy absorbed. We can use the equation:
Energy change (in Joules) = moles × molar enthalpy change (kJ/mol)
By rearranging the equation, we can find the number of moles:
Moles = Energy change (J) / molar enthalpy change (J/mol)
Since the given energy change is in kilojoules (kJ), we need to convert it to joules (J):
Energy change (J) = Energy change (kJ) × 1000
Now, let's calculate the moles of energy absorbed:
Energy change (J) = 682.2 kJ × 1000 = 682,200 J
Next, we need to find the molar enthalpy change of the given reaction. By examining the balanced chemical equation:
2C(s) + H2(g) + 227.4 kJ -> C2H2(g)
we can see that the molar enthalpy change is 227.4 kJ.
Now, we can substitute the values into the equation to find the moles of C2H2(g):
Moles = 682,200 J / 227,400 J/mol
Moles ≈ 2.9992 mol (rounded to four decimal places)
Therefore, approximately 2.9992 moles of C2H2(g) are produced when 682.2 kJ of energy are absorbed.