1: a, 2:a, 3:a, 4:c, 5:d, 6:d, 7:c;
Answer:
H3PO4 + 3KOH ----> K3PO4 + 3H2O
Explanation:
The valency of K element is + 1 while that of PO4 compound is -3
Hence, at least 3 K atoms are needed to combine with PO4 to form K3PO4 compound.
Hence, the revised equation will be
H3PO4 + 3KOH ----> K3PO4 + 3H2O
Now, the number of atoms and charges of each element is a given equation are equal on both the left and right hand side.
For this reaction to proceed, the following bond breaking should occur:
*one C-H bond
* one Cl-Cl bond
After, the following bond formations should occur:
*one C-Cl bond
*one H-Cl bond
Now, add the bond energies for the respective bond energies which can be found in the attached picture. For bond formations, energy is negative. For bond breaking, energy is positive.
ΔHrxn = (1)(413) + (1)(242) + 1(-328) + 1(-431) =
<em>-104 kJ</em>