The answer is C as it slowly destroys the ozone layer
Since the forward reaction is endothermic (heat is consumed in the reaction) that means that the enthalpy change for the forward reaction is a positive value.
Therefore, i would say that the reverse or backward reaction is exothermic (heat is released in the reaction to the sorroundings) and that the enthalpy change is a negative value.
When Cr dissolves in 1 M H₂Cr₂O₇
Cr(s) ⇄ Cr³⁺ + 3 e⁻
Cr₂O₇²⁻ + 14 H⁺ + 6 e⁻ ⇄ 2 Cr³⁺ + 7 H₂O
by multiplying the first equation by 2 and add the 2 equations;
The balanced redox reaction will be:
2 Cr(s) + Cr₂O₇²⁻(aq) + 14 H⁺(aq) → 4 Cr³⁺(aq) + 7 H₂O(l)
<span>The enthalpy of an intermediate step when used to produce an overall chemical equation should be manipulated in this way:
</span><span>Multiply the enthalpy by –1 if the chemical equation is reversed.
If the forward reaction requires energy, the reverse will produce energy.</span>
Answer:
21
Explanation:
Let us count the number of individual atoms for Na2S2O3 (the compound name):
Na: 2
S: 2
O: 3
This brings us to a total of 7 atoms for one molecule of sodium thiosulfate. For three of these compounds, we get 3*7=21
