According to the following reaction, how much energy is evolved during the reaction of 32.5g B2H6 and 72.5g Cl2? The molar mass of B2H6 is 27.67g/mol.
B2H6(g)+6Cl2(g)----->2BCl3(g)+HCl(g)
Delta H reaction=-1396
1396 WHAT?
Find the limiting reagent. Then
1396 whatever x (mass limiting reagent/molar mass limiting reagent) = ?
To calculate the amount of energy evolved during the reaction, you can use the given reaction's enthalpy change (ΔH) and the limiting reactant.
1. Calculate the moles of B2H6 using its molar mass:
Moles of B2H6 = mass / molar mass
Moles of B2H6 = 32.5g / 27.67g/mol = 1.17 mol B2H6
2. Calculate the moles of Cl2 using its molar mass:
Moles of Cl2 = mass / molar mass
Moles of Cl2 = 72.5g / 70.91g/mol = 1.02 mol Cl2
3. Determine the limiting reactant by comparing the moles of B2H6 and Cl2. The reactant with fewer moles is the limiting reactant.
In this case, Cl2 is the limiting reactant because it has fewer moles (1.02 mol).
4. Use the balanced chemical equation to determine the amount of energy evolved:
From the balanced chemical equation:
1 mole B2H6 reacts with 6 moles Cl2 to produce 2 moles BCl3 and 1 mole HCl.
Since 1 mole of B2H6 reacts with 6 moles of Cl2, the moles of BCl3 formed is given by:
Moles of BCl3 = (1.02 mol Cl2 / 6 mol Cl2) * 2 mol BCl3 = 0.34 mol BCl3
5. Calculate the energy evolved:
ΔH reaction is given as -1396 kJ for the reaction of B2H6 and Cl2 to form BCl3 and HCl.
Energy evolved = ΔH reaction * moles of BCl3 = -1396 kJ * 0.34 mol = -474.64 kJ
Therefore, the amount of energy evolved during the reaction of 32.5g B2H6 and 72.5g Cl2 is approximately -474.64 kJ.
To calculate the energy evolved during the reaction, we need to use the balanced equation and the molar masses of the reactants.
Step 1: Convert the given masses of B2H6 and Cl2 to moles.
The molar mass of B2H6 is 27.67 g/mol. We can calculate the number of moles of B2H6 using the formula:
moles of B2H6 = mass of B2H6 / molar mass of B2H6
So, for 32.5 g of B2H6:
moles of B2H6 = 32.5 g / 27.67 g/mol
Similarly, for Cl2:
moles of Cl2 = 72.5 g / molar mass of Cl2
Step 2: Determine the limiting reactant.
To find the limiting reactant, we compare the moles of B2H6 and Cl2 using the coefficients in the balanced equation (in this case, 1:6):
moles ratio (B2H6: Cl2) = moles of B2H6 / moles of Cl2
If the ratio is smaller than 1:6, B2H6 is the limiting reactant. If the ratio is larger than 1:6, Cl2 is the limiting reactant.
Step 3: Calculate the moles of the product formed.
Since B2H6 is the limiting reactant, we can use the balanced equation to determine the number of moles of the product formed. From the balanced equation, we see that the molar ratio between B2H6 and BCl3 is 1:2. So,
moles of BCl3 = 2 * moles of B2H6
moles of HCl = moles of B2H6
Step 4: Calculate the energy evolved using the equation:
Energy evolved = moles of BCl3 * Delta H reaction
Since Delta H reaction is given as -1396 kJ, the energy evolved can be calculated as:
Energy evolved = (2 * moles of B2H6) * -1396 kJ
Finally, substitute the calculated moles of B2H6 into the equation to determine the energy evolved.