Answer:
Elements are pure substances which are composed of only one type of atom. Compound are substances which are formed by two or more different types of elements that are united chemically in fixed proportions. ... Some of the examples of elements are Iron, Copper, Gold, etc. A few examples of compounds are NaOH, NaCl, etc.
Answer: Option (c) is the correct answer.
Explanation:
A limiting reagent is defined as a reagent that completely gets consumed in a chemical reaction. A limiting reagent limits the formation of products.
For example, we have given 5 mol of A and the reaction is 
Whereas when 4 mol B will react with 2 mol of A. Hence, 8 mol of B will react with 4 mol A as follows.
= 4 mol
As, the given moles of A is more than the required moles. Thus, it is considered as an excess reagent.
Hence, B is a limiting reagent because it limits the formation of products.
Thus, we can conclude that limiting reactant is the term used to describe the reactant that is used up completely and controls the amount of product that can be produced during a chemical reaction.
Answer: Option (b) is the correct answer.
Explanation:
In a chemical reaction, the bonds between the reactant molecules tend to break leading to the formation of new bonds to produce products.
So, in order to break the bonds between the reactant molecules, energy is required to overcome the attraction between the atoms.
To form new bonds, energy gets released when two atoms come closer to each other. Hence, formation of bond releases energy.
As in the given reaction it is shown that
< 0, that is, enthalpy change is negative. Hence, energy is released as it is an exothermic process.
Thus, we can conclude that the statement energy released as the bonds in the reactants is broken is greater than the energy absorbed as the bonds in the products are formed, is true about the bond energies in this reaction.