Did an oxidation-reduction reaction occur in the reaction between copper sulfate and sodium sulfide? cuso4 + na2s → cus + na2so4 a. this is a redox reaction because copper gained electrons. b. this is a redox reaction because sodium lost electrons. c. this is a redox reaction because sulfur gained electrons. d. this is not a redox reaction because no electrons were transferred. e. this is not a redox reaction because oxygen did not gain electrons. in which reaction is precipitation occurring? a. mgcl2(aq) + cuso4(aq) → cucl2(aq) + mgso4(aq) b. cdso4(aq) + k2s(aq) → cds(s) + k2so4(aq) c. naoh(aq) + nh4cl(aq) → nacl(aq) + nh4oh(aq) d. k2so4(aq) + naoh(aq) → k2oh(aq) + naso4(aq) e. hno3(aq) + koh(aq) → kno3(aq) + h2o(l)

1. It's not gonna be A, B, or C because  redox means when the electrons transfer both ways and a b and c dont show that. Bw d and E i'd go for D.

for 2.

I'd say B  because both reactants are acqueous while 1 product is solid so it would probably precipitate.

good luck da

Redox question

D. This is not a redox reaction because no electrons were transferred.

Explanation:

We can check whether a reaction is a redox reaction by determining the oxidation number of each atom on both sides of the arrow.

The oxidation number does not change for any atom, so this is not a redox reaction.

Precipitation question

B.  CdSO₄(aq) + K₂S(aq) → CdS(s) + K₂SO₄(aq)

Explanation:

A precipitation reaction occurs when an insoluble solid forms from the reaction of two substances in a solution.

This is the only reaction that forms a solid from two soluble reactants.