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.

they are made of gases.

they have a spherical shape.

they make energy through fusion.

c, liquids evaporate, creating a gas