Question

Sodium wire can be used to dry hexane solvent. (a) Write an equation for the reaction that occurs. (b) How might you destroy excess Na and what precautions should you take?

Short answer

(a) 2 Na + 2 H₂O → 2 NaOH + H₂; (b) React excess Na with ethanol carefully, wearing safety gear and ensuring good ventilation.

Step-by-step solution

Identify the Reaction Components

Sodium (Na) is a strong reducing agent and reacts with moisture (water) in the hexane solvent. The reaction involves sodium and water to produce sodium hydroxide (NaOH) and hydrogen gas (H₂).

Write the Balanced Reaction Equation

The balanced chemical equation for the reaction between sodium and water is: \[ 2 \, \text{Na} + 2 \, \text{H}_2\text{O} \rightarrow 2 \, \text{NaOH} + \text{H}_2 \] This equation shows that sodium reacts with water to form sodium hydroxide and hydrogen gas.

Evaluate a Method to Destroy Excess Sodium

To destroy excess sodium, it should be reacted carefully with alcohol like ethanol, which reacts less violently than water. The reaction forms sodium ethoxide and hydrogen gas: \[ \text{Na} + \text{C}_2\text{H}_5\text{OH} \rightarrow \text{C}_2\text{H}_5\text{ONa} + \text{H}_2 \]

List Required Precautions

When reacting sodium with ethanol, it's important to perform the reaction under controlled conditions. Use small amounts of sodium and ethanol at a time, wear protective equipment such as gloves and goggles, and perform the reaction in a well-ventilated area or fume hood to safely manage the release of hydrogen gas.

Key concepts

Sodium as a Reducing Agent

Sodium is a fascinating and mighty element in the world of chemistry, renowned for its role as a strong reducing agent. A reducing agent is a substance that donates electrons in a chemical reaction, reducing other substances and being oxidized itself in the process. Sodium is highly reactive, making it efficient at transferring electrons. When sodium wire is used to dry hexane solvent, it reacts with any moisture present, tearing apart water molecules and resulting in sodium hydroxide and hydrogen gas through a vigorous process. This reaction satisfies the moisture deficiency in the solvent but must be handled with care due to the rapid and intense nature of sodium's reactivity.

• Sodium donates its valence electron easily.
• This ability makes sodium effective in reducing other substances.
• Its reactivity can be harnessed but must be controlled carefully.

Remember, when wielding the power of sodium, it is crucial to anticipate its energetic eagerness to react!

Balanced Chemical Equations

Balanced chemical equations are essential in chemistry for representing the conservation of mass in a chemical reaction. They show the exact proportion of reactants and products involved. Let’s take a closer look at the balanced equation from our exercise: \[ 2 \, \text{Na} + 2 \, \text{H}_2\text{O} \rightarrow 2 \, \text{NaOH} + \text{H}_2 \]This equation denotes that two molecules of sodium (\( 2 \, \text{Na} \)) react with two molecules of water (\( 2 \, \text{H}_2\text{O} \)) to form two molecules of sodium hydroxide (\( 2 \, \text{NaOH} \)) and one molecule of hydrogen gas (\( \text{H}_2 \)). The principle of balancing chemical equations ensures that the number of atoms for each element is conserved from reactants to products. This is how chemists uphold the law of conservation of mass in every chemical transaction.

• Each side of the equation has equal numbers of each type of atom.
• Balancing equations maintain both the mass and charge balance.
• It's vital for calculating quantities needed or produced in reactions.

This neat organization helps chemists predict results, ensuring accuracy and efficiency in scientific experiments and industrial applications.

Safety Precautions in Chemical Reactions

Safety is paramount whenever handling chemicals, especially in reactions involving volatile substances like sodium. Sodium reacts energetically with water and even more so with acids or alcohols, producing hydrogen gas which is highly flammable. Consequently, safety precautions are non-negotiable. When destroying excess sodium, it's advised to convert it into a less reactive form, such as sodium ethoxide using ethanol.

• Conduct reactions with small quantities carefully to control the process.
• Always wear protective gear, namely gloves and eye protection.
• Ensure the workspace is well-ventilated or use a fume hood.

Staying safe means understanding the risks involved and taking steps to mitigate potential hazards. Never overlook these precautions, as they ensure your well-being and the smooth running of experiments!