Classify the following as acid-base reactions or oxidation-reduction reactions:
(a)na2s + hcl -> h2s + 2nacl
(b)2na + 2hcl -> h2 + 2nacl
(c)mg + cl2 = mgcl2
(d)mgo + 2hcl = h2o + mgcl2
(e)k3p+2o2 -> k3po4
(f)3koh +h3po4 -> k3po4 + 3h2o

Explanation:

(a)

This is acid base reaction because there is no change of oxidation state on either side of the reaction.

(b)

This is a oxidation reduction reaction because sodium in elemental state ( 0 oxidation state) oxidizes to Na⁺ in NaCl. Also H⁺ in HCl reduces to H° in H₂.

(c)

This is a oxidation reduction reaction because magnesium in elemental state ( 0 oxidation state) oxidizes to Mg²⁺ in MgCl₂. Also Cl° in Cl₂ reduces to Cl⁻ in  MgCl₂.

(d)

This is acid base reaction because there is no change of oxidation state on either side of the reaction.

(e)

This is a oxidation reduction reaction because phosphorous in P³⁻ in K₃P oxidizes to P⁵⁺ in K₃PO₄ and oxygen reduces.

(f)

This is acid base reaction because there is no change of oxidation state on either side of the reaction.

2h2o2--> 2h2o + o2

this reaction is of the spontaneous decomposition of hydrogen peroxide down into water and oxygen.

add 2 molecules of hydrogen peroxide and 2 molecules of water. since oxygen is naturally diatomic, the total number of atoms of each element is now the same on both sides of the equation so it is balanced.

this may not be entirely correct but let me know.