Answer:
Polyhydroxyl alcohols
Explanation:
Whenever we have several C-OH bonds, we have a polyhydroxyl alcohol. For example, if we have just one alcohol group, that is, an R-OH group, then the naming is simple, say, we have EtOH, it's ethanol.
The problem becomes more complicated when we have several hydroxyl groups present in the alcohol. Let's say we have an ethane molecule and we replace the hydrogen atoms of carbon 1 and 2 with hydroxyl groups. In that case, we have 1,2-ethanediol. Similarly, we can have triols etc.
That said, we have poly (several) hydroxyl groups and we can generalize this to having polyhydroxyl alcohols.
First write the molecular equation with states:
(NH4)2S (aq) + 2AgNO3(aq) → Ag2S (s) + 2NH4NO3
Now write a full ionic equation by separating into ions all substances that dissociate: anything (s) (g) or (l) does not dissociate
2NH4 + (aq) + S 2-(aq) + 2Ag+ (aq) + 2NO3- (aq) → Ag2S(s) + 2NH4 + (aq) + 2NO3- (aq)
To write the NET IONIC equation, inspect the full ionic equation above and delete anything that appears on both sides of the → sign:
Net ionic equation:
S 2-(aq) + 2Ag + (aq) → Ag2S(s)
Answer: Option (a) is the correct answer.
Explanation:
A decomposition reaction is defined as a reaction where a compound dissociates into two or more atoms.
For example, 
Whereas a chemical reaction in which two reactants combine together to result in the formation of a compound is known as a synthesis reaction.
For example,
is a synthesis reaction.
Thus, we can conclude that the statement chemical reaction A, because the reactant is a compound identifies the decomposition reaction and describes a substance is involved.