Which two properties are more typical of molecular compounds than of ionic compounds? 1. they are gases or liquids at room temperature. 2. they have high melting points. 3. solids do not conduct electricity, but liquids do. 4. atoms share electrons?

The answer is 1 and 4

Explanation:

This question is basically referring to the difference between covalent compounds and electrovalent/ionic compounds. This is because covalent compounds form molecules while ionic compounds do not.

Covalent compounds are compounds formed as a result of covalent combination which involves the sharing of valence electrons between two constituent atoms. These shared electrons between two atoms are called shared pair. They are liquids or gases at room temperature. For example water (H20). The two hydrogen atoms in water share there respective electron with the two unpaired electrons on the outermost shell of the oxygen atom. When these atoms share there electrons with each other, they eventually form a molecule

Ionic compounds are compounds formed as a result of ionic bond which involves transfer of electrons from one atom (the donor), to another atom (the acceptor). The donor atom after donating electron(s) becomes positively charged while the acceptor becomes negatively charged after receiving the electron(s), these charged particles do not form a molecule but remain as ions (hence the reason for the name ionic) and when dissolved in water (as they are usually solids at room temperature) readily conduct electricity. Example is common salt (NaCl), sodium (Na) donates the valence electron on its outermost shell to become sodium ion (Na+) while chlorine receives this electron and then becomes negatively charged (Cl-).

From the above, it is clear that molecular compounds are generally gases or liquids at room temperature and there constituent atoms share electrons.

the enthalpy of formation of water is given as -285.8kj/mol, which states that the enthalpy of formation is negative.

negative enthalpy of formation indicates that the heat is released during the reaction process. the heat is released from reaction to the surroundings the enthalpy is expressed with a negative sign with the energy given out in the reaction process.

the formation of water takes place by giving out heat which is -285.8 kj/mol.

1 is the answer to this problem