Which of the following reactions do not
involve electrons being either lost or gained
by any of the reactants involved in the
reaction?
a 2 na + 2 h2o → 2 naoh + h2
b k20→2 k+ o2
c ca + f2 + caf2
d agno3 + licl → agcl + lino3

It's D.

Explanation:

That would be choice D which might be called a double decomposition reaction - an exchange of ions where no electrons are lost or gained. The silver chloride appears as a white precipitate.

The correct answer is AgNO₃ + LiCl → AgCl + LiNO₃ (option D)

Explanation:

A double displacement reaction is that two elements found in different compounds exchange positions, forming two new compounds. These chemical reactions do not present changes in the number of oxidation or relative load of the element.  Generally the exchange occurs between reagents that are ionic compounds in solution, where the anions and cations of the compounds are exchanged.

Double displacement reactions follow the following general chemical equation:

AB + CD → AD + CB

The initial compounds AB and CD react by exchanging "their partners" and thus form two new compounds: AD and CB.

AgNO₃ + LiCl → AgCl + LiNO₃ is a double displacement reaction,  where the anions and cations that exchange positions are Ag⁺, Li⁺, NO₃⁻ and Cl⁻.

we can conclude that the melting point of table salt is above room temperature (it's actually 801 deg c). the melting point of mercury must be below room temperature (- 39 deg c).