In which of the following pairs of compounds are both members of the pair molecular compounds?

PCl3 and LiBr
CCl4 and KOH
NaH and CaF2
Please explain. thank you so much

Molecular means largely covalent.

PCl3 covalent but LiBr ionic
CCl4 covalent but KOH ionic
NaH ionic and CaF2 ionic

I don't think any of them are.

Molecular compounds are formed when elements from the nonmetal group combine together. In contrast, ionic compounds are formed when elements from the metal and nonmetal groups combine together, resulting in the transfer of electrons.

Let's go through each pair of compounds:

1. PCl3 and LiBr:
- PCl3 contains the elements phosphorus (a nonmetal) and chlorine (also a nonmetal). Therefore, it is a molecular compound.
- LiBr contains lithium (a metal) and bromine (a nonmetal). Therefore, it is an ionic compound.
Conclusion: Only PCl3 is a molecular compound.

2. CCl4 and KOH:
- CCl4 contains carbon (a nonmetal) and chlorine (also a nonmetal). Therefore, it is a molecular compound.
- KOH contains potassium (a metal) and hydroxide (a polyatomic ion consisting of an oxygen atom and a hydrogen atom bonded together). Therefore, it is an ionic compound.
Conclusion: Only CCl4 is a molecular compound.

3. NaH and CaF2:
- NaH contains sodium (a metal) and hydrogen (a nonmetal). Therefore, it is an ionic compound.
- CaF2 contains calcium (a metal) and fluorine (also a nonmetal). Therefore, it is an ionic compound.
Conclusion: Neither NaH nor CaF2 are molecular compounds.

In summary, the only pair of compounds that are both molecular compounds is PCl3 and LiBr.

To determine whether a compound is molecular or not, you need to understand the difference between molecular and ionic compounds.

Molecular compounds consist of atoms that share electrons, forming covalent bonds. These compounds typically consist of nonmetals or a combination of nonmetals and hydrogen.

On the other hand, ionic compounds are formed by the transfer of electrons between atoms, resulting in the formation of positive and negative ions. Ionic compounds usually consist of a metal combined with a nonmetal or a polyatomic ion.

Let's analyze each pair of compounds:

1. PCl3 and LiBr:
- PCl3 contains phosphorus (a nonmetal) and chlorine (also a nonmetal). Therefore, PCl3 is a molecular compound.
- LiBr consists of lithium (a metal) and bromine (a nonmetal). This combination results in the formation of ions (Li+ and Br-). Hence, LiBr is an ionic compound.

2. CCl4 and KOH:
- CCl4 contains carbon (a nonmetal) and chlorine (a nonmetal), making it a molecular compound.
- KOH is composed of potassium (a metal) and hydroxide (a polyatomic ion consisting of oxygen and hydrogen). Therefore, KOH is an ionic compound.

3. NaH and CaF2:
- NaH contains sodium (a metal) and hydrogen (a nonmetal). It undergoes ionic bonding and forms sodium ions (Na+) and hydride ions (H-), so NaH is an ionic compound.
- CaF2 consists of calcium (a metal) and fluorine (a nonmetal). When combined, they form calcium ions (Ca2+) and fluoride ions (F-), resulting in an ionic compound.

Based on the analysis:
- Only the pair PCl3 and LiBr has the molecular compound as both members of the pair.