How are the following reaction described?

#(a).HX(aq) + MOH(aq)rarrMX + H_2O#

#(b).M(s)+H_2OrarrMOH+ 1/2H_2#

#(c).Fe + 2Fe^(3+)rarr3Fe^(2+)#

What does #(aq)# as a descriptor of a reactant or product?

1 Answer
Feb 9, 2017

Answer:

#"(a) an acid-base reaction"#

Explanation:

#"(b) a redox reaction"#

#"(c) a comproportionation reaction"#.

#(aq)# simply means the #"aquated ion"#, or the ionic species in aqueous solution. For #Cu(SO_4)(aq)# this means #Cu^(2+)# and #SO_4^(2-)#, where in aqueous solution #Cu^(2+)# exists as the coordination complex #[Cu(OH_2)_6]^(2+)#, which has a truly beautiful blue colour.

In #"(c)"#, this is a subset of redox reaction, but here, instead of one species being reduced, and another species oxidized, which conventionally occurs, as for #"(b)"#, here the reactants are in different oxidations states, i.e. #N^(-III)# in #"ammonia"#, and #N^(+I)# in #"dinitrogen monoxide"# (note that we could formally assign oxidation states of #N^0#, and #N^(+II)# but the average oxidation is #N^(+I)#), these formally exchange electrons so that their product gives #N^(+I)#, a formal comproportionation.

I assume you are a first/second year undergrad. If you are an A-level student you don't need to know about #"comproportionation"#.