citric acid is in most foods
Answer:
HCN - Hydrogen cyanide The conjugate acid of CN- is HCN. HCN stands for hydrogen cyanide. The conjugate acids are a combination of a strong acid and a low base.
- Endothermic reaction means the reactant side takes heat from surrounding and get decomposed i.e ∆H=-ve
- If the equation is exothermic then it means the reactant is happy to decompose .But it's not as it's endothermic
Now
- HgO is Omitted from our solution option.
Hg is a atom so no bonds hence no bond strength occurs.
- O_2 is a molecule and so it's our answer .
Volume of NaOH required to react = 145.5 ml
<h3>Further explanation</h3>
Reaction
CO₂(g)
+ 2 NaOH(aq) ⇒Na₂CO₃(aq) + H₂O(l)
The volume of CO₂ : 0.45 L
mol CO₂ at STP (O C, 1 atm) ⇒ at STP 1 mol gas 22.4 L :

From the equation, the mol ratio of CO₂ : NaOH = 1 : 2, so mol NaOH :

Then volume of NaOH :

The change of the statue of liberty from copper to green is an example of a chemical change.
<h3>Physical and chemical change</h3>
A physical change does not involve the formation of new substances and the composition of the substance does not change. However, in a chemical change, a new substance is formed and the composition of the substance changes.
The statement that reflect a chemical change is;
- The Statue of Liberty’s metal tarnishes from copper to green.
Learn more about physical and chemical change: brainly.com/question/13316655