Question

Pick the correct products for the following reaction acid + metal reaction: 2 HNO3 + Co -->

1. No products formed
2. Co(NO3)2 + H2
3. HNO3 + Co
4. CoH2 + 2NO3

Answer 1

Answer:

2. Co(NO3)2 + H2

Explanation:

Hello,

In this case, we are evidencing a simple displacement reaction wherein the cobalt is able displace the hydrogen to produce cobalt (II) nitrate and gaseous hydrogen as a result of cobalt's higher activity:

$2 HNO_3 + Co\rightarrow Co(NO_3)_2+H_2$

Therefore, answer is 2. Co(NO3)2 + H2.

Best regards.

Answer 2

Answer:

Co(NO3)2 + H2

Explanation:

The full balanced reaction equation of the reaction is shown below;

2HNO3(aq) + Co (s)-------> Co(NO3)2(aq) + H2(g)

One of the properties of metals is that metals displace hydrogen from dilute acids. This property is only exhibited by metals which are above hydrogen in the electrochemical series.

This implies that the ability to displace hydrogen from aqueous solution depends on the reduction potential of the metal. Metals having more negative reduction potentials than hydrogen can displace it from aqueous solution.

Cobalt II having a negative reduction potential of about -0.28 V can displace hydrogen from a dilute acid. Hence the answer.