<span>The choices are as follows:
h2o + 2o2 = h2o2
fe2o3 + 3h2 = 2fe + 3h2o
al + 3br2 = albr3
caco3 = </span><span>cao + co2
The correct answers would be the second and the last option. The equations that are correctly balanced are:
</span> fe2o3 + 3h2 = 2fe + 3h2o
caco3 = cao + co2
To balance, it should be that the number of atoms of each element in the reactant and the product side is equal.
Answer: released to; absorbed from
- In an exothermic reaction, energy is released to the surroundings.
- In an endothermic reaction, energy is absorbed from the surroundings.
Explanation:
An exothermic reaction is a chemical reaction that occurs spontaneously and brings about the release of energy to the surroundings. Hence, the reacting vessel feels hot as the reaction proceeds.
An endothermic reaction, on the other hand, does not occur spontaneously and proceed only when energy is absorbed from the surroundings. Hence, the reacting vessel feels cold as the reaction proceeds.
Answer:
1. The correct option is;
c. maintains charge balance in the cell
2. The correct option is;
c. +3.272 V
Explanation:
The aqueous solution in a galvanic cell is the electrolyte which is a ionic solution containing that permits the transfer of ions between the separated compartment of the galvanic cell such that the overall system is electrically neutral
Therefore, the aqueous solution maintains the charge balance in the cell
2. Here we have;
B₂ + 2e⁻ → 2B⁻ Ecell = 0.662 V
A⁺ + 1e⁻ → A Ecell = -1.305 V
Hence for the overall reaction, we have;
2A + B₂ → 2AB gives;
(0.662) - 2×(-1.305) = +3.272 V.
An atom is the basic unit of matter.
