Explanation:
reaction cannot be both endothermic and exothermic at the same time.
3. Cl₂ + 2KI --> 2KCl + I₂
Cl = 2 Cl = 2
K = 2 K = 2
I = 2 I = 2
4. 2NaCl --> 2Na + Cl₂
Na = 2 Na = 2
Cl = 2 Cl = 2
5. 4Na + O₂ --> 2Na₂O
Na = 4 Na = 4
O = 2 O = 2
6. 2Na + 2HCl --> H₂ + 2NaCl
Na = 2 Na = 2
H = 2 H = 2
Cl = 2 Cl = 2
7. 2K + Cl₂ --> 2KCl
K = 2 K = 2
Cl = 2 Cl = 2
The number of sigma and pi bonds are,
Sigma Bonds =
16 Pi Bonds =
3Explanation: Every first bond formed between two atoms is sigma. Pi bond is formed when already a sigma bond is there. While in case of Alkyne (triple Bond) there is one sigma and one pi bond already present, so the third bond is formed by second side-to-side overlap of orbitals, hence, a second pi bond is formed.
Below all black bonds are sigma bonds, while in alkene there is one pi bond and in alkyne there are two pi bonds.