Question

Uranium hexafluoride (UF \(_{6}\) ) reacts with water to make uranyl fluoride \(\left(\mathrm{UO}_{2} \mathrm{~F}_{2}\right)\) and \(\mathrm{HF}\). Balance the following reaction: \(\mathrm{UF}_{6}+\mathrm{H}_{2} \mathrm{O} \rightarrow \mathrm{UO}_{2} \mathrm{~F}_{2}+\mathrm{HF}\)

Short answer

The balanced equation is: UF _{6} + 2 _{H}_{2}O _{→} UO _{2} _{F}_{2} + 4 _{HF}.

Step-by-step solution

Write the Unbalanced Equation

The first step is to write down the unbalanced chemical equation:\[\text{UF}_6 + \text{H}_2\text{O} \rightarrow \text{UO}_2\text{F}_2 + \text{HF}\]

Identify the Atoms in the Reaction

List the different types of atoms present on the reactants side and the products side: U (uranium), F (fluorine), H (hydrogen), and O (oxygen).

Balance Uranium Atoms

There is 1 uranium atom on the reactants side and 1 uranium atom in \(\text{UO}_2\text{F}_2\) on the products side, so no change is needed for uranium.

Balance Fluorine Atoms

There are 6 fluorine atoms from \(\text{UF}_6\) on the reactants side and a total of \(2 + x\) fluorine atoms from \(\text{UO}_2\text{F}_2\) and \(x\) \(\text{HF}\) on the products side. Set up the equation:\[6 = 2 + x\]Solving gives \(x = 4\), so add a coefficient of 4 in front of HF: \[\text{UF}_6 + \text{H}_2\text{O} \rightarrow \text{UO}_2\text{F}_2 + 4\text{HF}\]

Balance Hydrogen Atoms

Now, the right side has \(4\) hydrogen atoms (from \(4\text{HF}\)), so you need \(2\) water molecules to provide those \(4\) hydrogen atoms. Change the coefficient for \(\text{H}_2\text{O}\):\[\text{UF}_6 + 2\text{H}_2\text{O} \rightarrow \text{UO}_2\text{F}_2 + 4\text{HF}\]

Balance Oxygen Atoms

Check the oxygen atoms. On the left, there are 2 from \(2\text{H}_2\text{O}\), and on the right, there are 2 in \(\text{UO}_2\text{F}_2\). Oxygen is balanced.

Confirm the Balanced Equation

Now, verify that all atoms are balanced: 1 Uranium, 6 Fluorine, 4 Hydrogen, and 2 Oxygen atoms on both sides. The balanced equation is:\[\text{UF}_6 + 2\text{H}_2\text{O} \rightarrow \text{UO}_2\text{F}_2 + 4\text{HF}\]

Key concepts

Chemical Reactions

A chemical reaction is a process where substances (reactants) are transformed into different substances (products). This transformation happens at a molecular level as bonds are broken in reactants and new bonds are formed to create the products. In our example, uranium hexafluoride (UF\( _6 \)) reacts with water (H\( _2 \)O) and undergoes a chemical transformation resulting in uranyl fluoride (UO\( _2 \)F\( _2 \)) and hydrogen fluoride (HF). Understanding the representation of chemical reactions through chemical equations is crucial:

• Reactants are written on the left side of the equation.
• Products are written on the right side of the equation.
• An arrow indicates the direction of the transformation.

Chemical equations must be balanced to obey the Law of Conservation of Mass, which states that matter cannot be created or destroyed. Balancing equations ensures the same number of each type of atom is present on both sides of the equation, maintaining mass consistency.

Stoichiometry

Stoichiometry involves the calculation of reactants and products in chemical reactions. It relies on the concept of a balanced equation to provide relationships between the amounts of reactants used and products formed.For the reaction UF\( _6 \) + H\( _2 \)O → UO\( _2 \)F\( _2 \) + HF, stoichiometry helps us determine the amount of each substance involved:

• Coefficients: The numbers placed before compounds in equations denote the number of molecules (or moles) of each substance. In the balanced equation UF\( _6 \) + 2H\( _2 \)O → UO\( _2 \)F\( _2 \) + 4HF, these coefficients are crucial for stoichiometric calculations.
• Mole Ratio: This ratio is determined from the coefficients and is used to calculate how many moles of a reactant will produce a given number of moles of a product.

Understanding stoichiometry allows chemists to predict the amounts of products that will form in a reaction or the amounts of reactants needed to produce a desired amount of product.

Uranium Hexafluoride

Uranium hexafluoride (UF\( _6 \)) is an important compound in the nuclear industry. Its primary use is in the production of fuel for nuclear reactors and atomic bombs. UF\( _6 \) is used in the enrichment process where uranium is converted to a gaseous form to separate isotopes.Here are some interesting aspects about UF\( _6 \):

• Physical State: UF\( _6 \) is a solid at room temperature but sublimates (turns directly from a solid to a gas) at slightly higher temperatures.
• Reactivity: It reacts with water to produce uranyl fluoride and hydrogen fluoride, as demonstrated in the balanced reaction UF\( _6 \) + 2H\( _2 \)O → UO\( _2 \)F\( _2 \) + 4HF. This reaction is significant in processing UF\( _6 \) for further use.
• Safety Considerations: Both UF\( _6 \) and HF are highly corrosive and toxic, requiring careful handling and the use of appropriate safety measures.

Understanding the chemical behavior and properties of UF\( _6 \) is crucial for its safe and effective use, especially in critical applications like nuclear energy production.