<span>From the above given choices :
melting is an endothermic process</span>
Answer: C2H2
Explanation: Because each of the lines represent one bond, and because there are three lines (bonds) between the carbons, it means that they are bonded by three bonds, also known as a triple bond.
We are going to use table salt, NaCl as an example.
(s) = solid, eg the salt you put on your food is a crystalline solid.
(l) = liquid, if you melt salt it take on a liquid form
(g) = gaseous, if you put enough energy in the salt will turn into a gas.
(aq) = aqueous, meaning in water or another solvent. If you put some table salt in water and stir it, it will dissolve, the NaCl molecules dont get destroyed but they dissolve becoming part of the liquid.
An acid has several definitions one would be that it is a proton donor and an electron donor. Also, it said to produce an H+ ion when in solution. For nitric acid in solution, it dissociates into ions which are NO- ions and H+ ions. So, it must be an acid. It has a dissociation reaction:
HNO3 = H+ + NO3-
