Periodic Table and oxidising agent

[Priyadarshini]

Homework Statement

(i) An element that has a molecule which contains exactly four atoms.
(ii) An element that reacts with water to give a solution that can behave as an oxidising agent.

Homework Equations

The Attempt at a Solution

(i) Shouldn't it be boron? Boron forms BF3 which has four atoms.
(ii) Mg? Because Mg forms Mg+2 ions when it forms an oxide/hydroxide with water. This will cause it to reduce itself, oxidising other compounds, making it an oxidising reagent.[/B]

 

[Ygggdrasil]

Your answer to (i) sounds fine, but in (ii) it says that the solution formed after reacting with water should be an oxidizing agent. While you are correct that Mg becomes oxidized when reacting with water, the resulting solution of Mg(OH)2 is not an oxidizing reagent.

 

[Bystander]

Single element. Tetra-atomic. Try again.

 

[Priyadarshini]

Single element. Tetra-atomic. Try again.

Ohhhh, I see. Phosphorous, it forms P4

 

[Priyadarshini]

Your answer to (i) sounds fine, but in (ii) it says that the solution formed after reacting with water should be an oxidizing agent. While you are correct that Mg becomes oxidized when reacting with water, the resulting solution of Mg(OH)2 is not an oxidizing reagent.

Is Mg(OH)2 a reducing agent then? Or neither?
How would I go about answering this question?

 

[Bystander]

Phosphorous, it forms P4

Correct.

 

[Merlin3189]

...reacts with water to give a solution that can behave as an oxidising agent.
... How would I go about answering this question?

What is an oxidising agent, in general terms? But I don't know how much that will help you, unless you already know an answer!
You might think about which elements behave as oxidising agents, then look into their reaction with water.
Otherwise I think it is just general knowledge of common chemicals which might tell you.

I myself don't know THE answer, just an answer.

 

[Ygggdrasil]

Is Mg(OH)2 a reducing agent then? Or neither?
How would I go about answering this question?

Mg(OH)2 is neither a strong reducing agent nor oxidizing agent. Honestly, I'm not sure how you're supposed to deduce the answer without checking each element individually. I will give the hint to think of common household oxidizing agents (in particular the smell of one element is associated with this oxidizing agent).

 

[Priyadarshini]

What is an oxidising agent, in general terms? But I don't know how much that will help you, unless you already know an answer!
You might think about which elements behave as oxidising agents, then look into their reaction with water.
Otherwise I think it is just general knowledge of common chemicals which might tell you.

I myself don't know THE answer, just an answer.

Oxidising agents oxidise other elements or compounds and reduce themselves in the process.

 

[Priyadarshini]

What is an oxidising agent, in general terms? But I don't know how much that will help you, unless you already know an answer!
You might think about which elements behave as oxidising agents, then look into their reaction with water.
Otherwise I think it is just general knowledge of common chemicals which might tell you.

I myself don't know THE answer, just an answer.

Mg(OH)2 is neither a strong reducing agent nor oxidizing agent. Honestly, I'm not sure how you're supposed to deduce the answer without checking each element individually. I will give the hint to think of common household oxidizing agents (in particular the smell of one element is associated with this oxidizing agent).

In the question, are they asking for an element that can act as an oxidising agent? Or must the element after reacting with water, be able to act as an oxidising agent?
Common household oxidising agents, bleach?

 

[Bystander]

Also known as what?

 

[Ygggdrasil]

In the question, are they asking for an element that can act as an oxidising agent? Or must the element after reacting with water, be able to act as an oxidising agent?

After the element reacts with water, the resulting product must be able to act as an oxidizing agent. It doesn't matter whether the originial element was an oxidizing agent or not.

Common household oxidising agents, bleach?

Yes, you are on the correct track with that thought.

 

[Priyadarshini]

Also known as what?

After the element reacts with water, the resulting product must be able to act as an oxidizing agent. It doesn't matter whether the originial element was an oxidizing agent or not.
Yes, you are on the correct track with that thought.

NaClO, sodium chlorate (I)

 

[Ygggdrasil]

NaClO, sodium chlorate (I)

Right. Bleach is sodium hypochlorite (NaClO). Sodium chlorate is NaClO3.

What element, when reacted with water might form something similar to sodium hypochlorite.

 

[Priyadarshini]

Right. Bleach is sodium hypochlorite (NaClO). Sodium chlorate is NaClO3.

What element, when reacted with water might form something similar to sodium hypochlorite.

Cl2 and water would give HCl and HClO, so chlorine is the answer!
Thank you!