Most covalent compounds have relatively low melting points and boiling points. Covalent compounds usually have lower enthalpies of fusion and vaporization than ionic compounds. Covalent compounds tend to be more flammable than ionic compounds. When dissolved in water, they don't conduct electricity.
Source: https://socratic.org/questions/what-are-the-main-properties-of-covalent-compounds
Answer: The bonds that hold molecules together break apart and form new bonds.
Explanation:
Answer 1 : The balanced complete ionic equation will be,
![NaOH(aq)+HNO_3(aq)\rightarrow H_2O(l)+NaNO_3(aq)](https://tex.z-dn.net/?f=NaOH%28aq%29%2BHNO_3%28aq%29%5Crightarrow%20H_2O%28l%29%2BNaNO_3%28aq%29)
![Na^+(aq)+OH^-(aq)+H^+(aq)+NO_3^-(aq)\rightarrow H_2O(l)+Na^+(aq)+NO_3^-(aq)](https://tex.z-dn.net/?f=Na%5E%2B%28aq%29%2BOH%5E-%28aq%29%2BH%5E%2B%28aq%29%2BNO_3%5E-%28aq%29%5Crightarrow%20H_2O%28l%29%2BNa%5E%2B%28aq%29%2BNO_3%5E-%28aq%29)
By removing the spectator ion in this equation, we get the balanced ionic equation.
![OH^-(aq)+H^+(aq)\rightarrow H_2O(l)](https://tex.z-dn.net/?f=OH%5E-%28aq%29%2BH%5E%2B%28aq%29%5Crightarrow%20H_2O%28l%29)
Answer 2 : The balanced net ionic equation will be,
![2Na_3PO_4(aq)+3NiCl_2(aq)\rightarrow Ni_3(PO_4)_2(s)+6NaCl(aq)](https://tex.z-dn.net/?f=2Na_3PO_4%28aq%29%2B3NiCl_2%28aq%29%5Crightarrow%20Ni_3%28PO_4%29_2%28s%29%2B6NaCl%28aq%29)
![6Na^+(aq)+2PO_4^{3-}(aq)+3Ni^+(aq)+6Cl^-(aq)\rightarrow Ni_3(PO_4)_2(s)+6Na^+(aq)+6Cl^-(aq)](https://tex.z-dn.net/?f=6Na%5E%2B%28aq%29%2B2PO_4%5E%7B3-%7D%28aq%29%2B3Ni%5E%2B%28aq%29%2B6Cl%5E-%28aq%29%5Crightarrow%20Ni_3%28PO_4%29_2%28s%29%2B6Na%5E%2B%28aq%29%2B6Cl%5E-%28aq%29)
By removing the spectator ion in this equation, we get the balanced ionic equation.
![2PO_4^{3-}(aq)+3Ni^+(aq)\rightarrow Ni_3(PO_4)_2(s)](https://tex.z-dn.net/?f=2PO_4%5E%7B3-%7D%28aq%29%2B3Ni%5E%2B%28aq%29%5Crightarrow%20Ni_3%28PO_4%29_2%28s%29)
Answer 3 : The balanced net ionic equation will be,
![2Na_3PO_4(aq)+3NiCl_2(aq)\rightarrow Ni_3(PO_4)_2(s)+6NaCl(aq)](https://tex.z-dn.net/?f=2Na_3PO_4%28aq%29%2B3NiCl_2%28aq%29%5Crightarrow%20Ni_3%28PO_4%29_2%28s%29%2B6NaCl%28aq%29)
![6Na^+(aq)+2PO_4^{3-}(aq)+3Ni^+(aq)+6Cl^-(aq)\rightarrow Ni_3(PO_4)_2(s)+6Na^+(aq)+6Cl^-(aq)](https://tex.z-dn.net/?f=6Na%5E%2B%28aq%29%2B2PO_4%5E%7B3-%7D%28aq%29%2B3Ni%5E%2B%28aq%29%2B6Cl%5E-%28aq%29%5Crightarrow%20Ni_3%28PO_4%29_2%28s%29%2B6Na%5E%2B%28aq%29%2B6Cl%5E-%28aq%29)
By removing the spectator ion in this equation, we get the balanced ionic equation.
![2PO_4^{3-}(aq)+3Ni^+(aq)\rightarrow Ni_3(PO_4)_2(s)](https://tex.z-dn.net/?f=2PO_4%5E%7B3-%7D%28aq%29%2B3Ni%5E%2B%28aq%29%5Crightarrow%20Ni_3%28PO_4%29_2%28s%29)
Balanced equations : Balanced equations are the equations in which the number of individual elements present on the reactant side must be equal to the number of individual elements present on the product side.
Spectator ions : It is defined as the ions which do not participate in the chemical reaction. These ions exists in the same form on both the sides of the reaction.