Answer:
In a chemical reaction, reactants that are not used up when the reaction is finished are called excess reagents. The reagent that is completely used up or reacted is called the limiting reagent, because its quantity limits the amount of products formed.
Explanation:
C. The number of neutrons
Since Carbon 12 has 6 neutrons
And carbon 13 has 7 neutrons.
You know that elements have equal protons (atomic number) and electrons
Answer:
B) Heat is given off.
Explanation:
When heat is given off, a chemical change must have occurred and such a reaction is termed an exothermic reaction.
A chemical change is one in which;
- the process is not easily reversible
- leads to the production of new kinds of matter
- involves change in mass
- requires a considerable amount of energy.
Most chemical reactions are accompanied by heat changes.
Answer:
Aldehyde and ketone both react with alcohols (2 equivalent) in the presence of acid catalyst to give acetals.
Explanation:
Alcohols are poor nucleophiles and so protonation of the carbonyl oxygen used to make the carbonyl carbon a stronger electrophile. Addition of the first equivalent of alcohols gives a hemiacetal,
Addition of the second equivalent of alcohol is accompanied by loss of one molecule water to yield the produce acetal.
