Reaction of Sodium Metal and Water

In summary: The concentration of hydrogen peroxide can be easily determined by redox titration with permanganate in acidic solution."In summary, when sodium is dropped into water, aqueous sodium hydroxide and hydrogen gas are produced. Sodium metal acts as a reducing agent, there are no spectator ions, and the electrical conductivity of the aqueous solution increases as electrolytes are formed. However, not all elements that are oxidized are necessarily reducing agents in general.
  • #1
Qube
Gold Member
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1

Homework Statement



When sodium is dropped into water, aqueous sodium hydroxide and hydrogen gas are produced. Which of the following are correct regarding this reaction?

1) Sodium metal is the reducing agent.
2) There are no spectator ions.
3) In the balanced net ionic equation, all coefficients are unity.
4) The electrical conductivity of the aqueous part increases during the reaction.

Homework Equations



Oxidation is loss of electrons. Reduction is gain of electrons. Reducing agents give electrons. Oxidizing agents take electrons.

Unity = 1.

The Attempt at a Solution



1) Sodium metal starts with an oxidation number of 0 since it's by itself (in its elemental form). On the product side however sodium in NaOH has a +1 oxidation state. Sodium has been oxidized; it has lost electrons. Sodium has given up electrons to the oxygen and hydrogen too, so sodium is a reducing agent. Not all elements that have been oxidized are reducing agents, correct?

2) I'm not seeing many ions except the ions that form on the product side of the equation, so there can't be any spectator ions, since spectator ions are defined to exist as reactants and as products.

3) There isn't a net ionic equation because the only ions are on the product side of the equation.

4) Yes, aqueous sodium hydroxide is produced, and it is an electrolyte.

So I conclude that yes, Na metal acts as a reducing agent, having reduced the oxygen and hydrogen by giving them an electron; that yes, there are no spectator ion; that yes, the electrical conductivity of the solution increases as electrolytes are formed. Is my reasoning all correct?
 
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  • #2
Looks OK to me.

I admit I don't like some of these questions. They are nitpicky without adding any value.
 
  • #3
Great! But are all elements which are oxidized also reducing agents?
 
  • #4
Qube said:
Great! But are all elements which are oxidized also reducing agents?

In the particular reaction they were oxidized - yes.. Doesn't mean they are reducing agent in general.

Hydrogen peroxide - which is a known oxidizing agent - is sometimes a reducing agent. Compare titrations.info/permanganate-titration-hydrogen-peroxide
 
  • #5


Your reasoning is mostly correct, but there are a few points that could use clarification:

1) Sodium is indeed a reducing agent in this reaction, as it loses electrons and reduces the oxidation state of oxygen and hydrogen. However, it is important to note that not all elements that are oxidized are reducing agents. For example, in a reaction where oxygen is reduced to water, oxygen is not considered a reducing agent because it is not actively giving electrons to another species. In the case of sodium, it is actively giving electrons to oxygen and hydrogen, making it a reducing agent.

2) You are correct that there are no spectator ions in this reaction, as all the ions present are involved in the reaction. However, it is worth noting that spectator ions can exist in both reactants and products, as long as they are not involved in the actual chemical reaction. In this case, since there are no ions present in the reactants, there cannot be any spectator ions.

3) There is a net ionic equation for this reaction, which is: 2Na + 2H2O → 2NaOH + H2. The net ionic equation only includes the species that are actively participating in the reaction, in this case, sodium and water.

4) Yes, the electrical conductivity of the solution will increase as electrolytes are formed. However, it is important to note that the electrical conductivity is not solely due to the presence of sodium hydroxide, but also due to the presence of dissolved sodium ions and hydroxide ions, which are also present in the solution.
 

Related to Reaction of Sodium Metal and Water

What happens when sodium metal reacts with water?

When sodium metal reacts with water, a vigorous reaction occurs. The sodium metal will react with the water to form sodium hydroxide (NaOH) and hydrogen gas (H2). This reaction is highly exothermic and can produce enough heat to ignite the hydrogen gas.

Why does sodium metal react with water?

Sodium metal is a highly reactive element and is stored in oil to prevent it from reacting with moisture in the air. When sodium metal comes in contact with water, the strong attraction between the positive sodium ions and negative water molecules causes a violent reaction to occur.

What safety precautions should be taken when conducting the reaction of sodium metal and water?

Due to the highly exothermic nature of the reaction, it is important to wear protective gear such as goggles and gloves. The reaction should also be conducted in a well-ventilated area and away from any flammable materials. It is also important to use small pieces of sodium metal and add them to the water slowly to control the reaction.

What is the chemical equation for the reaction of sodium metal and water?

The chemical equation for the reaction of sodium metal and water is 2Na + 2H2O -> 2NaOH + H2. This means that for every two moles of sodium metal that react, two moles of water are consumed to produce two moles of sodium hydroxide and one mole of hydrogen gas.

What are the industrial uses of the reaction between sodium metal and water?

The reaction between sodium metal and water is used in the production of hydrogen gas, which has many industrial applications. Sodium hydroxide, the other product of the reaction, is also commonly used in industries such as paper manufacturing, soap making, and water treatment.

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