Answer: CuI₂ + Br₂
Explanation:
1) The activity series F > Cl > Br > I means that F is the most active and I is the least active of those four elements (the halogens, group 17 in the periodic table).
The activity is a measure of how eager is an element to react compared to other elements in the series in a single replacement reaction.
2) Choice 1: CuI₂ + Br₂
Since the activity of Br is higher than that of I, Br will react with CuI₂, displacing I, which will be left alone, as per this chemical equation:
CuI₂ + Br₂ → CuBr₂ + I₂
Being I less active than Br, it cannot displace Br in CuBr₂.
3) Choice 2: Cl₂ + AlF₃
Being Cl less active than F, the former will not displace the latter, and the reaction will not proceed.
4) Choice 3: Br₂ + NaCl
Again, being Br less active than Cl, the former will not displace the latter, and the reaction will not proceed.
5) Choice 4: CuF₂ + I₂
Once more, being I less active than F, the former will not displace the latter, and the reaction will not proceed.
Propanoic acid formula is ch ch 2 so it has 8 bonds
Answer: heat required to raise the temperature
Explanation: Heat equation is represented as:

Q= heat required to raise the temperature
m= mass of the substance
c = heat capacity of substance

The whole Activity , poem and paragraph is missing in the question.
Answer:
(1) Liquid A
(2) Solid A
Explanation:
Using this part of the given poem
Substances and mixtures behave differently,
During boiling and melting most especially
Boiling point of substance is fixed while mixture is not
Substance melts completely but mixture does not
The boiling point of the Pure substance remain fixed after reaching its boiling point this is shown by Liquid A
Solid A is melting completely so Solid A is a pure substance.