Problem 97 - Chemistry Matter and Change

Question

Complete the following chemical equation. $$\mathrm{CuCl}_{2}(\mathrm{s})+\mathrm{Na}_{2} \mathrm{SO}_{4}(\mathrm{aq}) \rightarrow$$

Step-by-Step Solution

Answer

The balanced chemical equation is \(\mathrm{CuCl}_{2}(\mathrm{s}) + \mathrm{Na}_{2}\mathrm{SO}_{4}(\mathrm{aq}) \rightarrow \mathrm{CuSO}_{4}(\mathrm{aq}) + 2\mathrm{NaCl}(\mathrm{aq})\).

Step 1: Identify the reactants

In this chemical equation, we have copper(II) chloride, \(\mathrm{CuCl}_{2}(\mathrm{s})\), and sodium sulfate, \(\mathrm{Na}_{2}\mathrm{SO}_{4}(\mathrm{aq})\) as the reactants. These are the compounds that will undergo a chemical reaction.

Step 2: Predict the products

The reaction between \(\mathrm{CuCl}_{2}(\mathrm{s})\) and \(\mathrm{Na}_{2}\mathrm{SO}_{4}(\mathrm{aq})\) can typically result in a double displacement reaction. In this scenario, the cations and anions exchange partners, resulting in products \(\mathrm{CuSO}_{4}\) and \(\mathrm{NaCl}\).

Step 3: Write the balanced chemical equation

Write down the chemical equation resulting from the double displacement reactions: \[\mathrm{CuCl}_{2}(\mathrm{s}) + \mathrm{Na}_{2}\mathrm{SO}_{4}(\mathrm{aq}) \rightarrow \mathrm{CuSO}_{4}(\mathrm{aq}) + 2\mathrm{NaCl}(\mathrm{aq})\]. The \(\mathrm{CuSV} subdivision(\mathrm{aq})\) is soluble in water, and \(\mathrm{NaCl}(\mathrm{aq})\) is also soluble.

Step 4: Check the balancing of the equation

Ensure that the equation is balanced by counting the number of atoms of each element on both sides. There are 1 Cu, 2 Cl, 2 Na, 1 S, and 4 O atoms on both sides, ensuring coefficients are correctly used for balancing.

Key Concepts

Double displacement reaction

A double displacement reaction, also known as a metathesis reaction, occurs when the cations and anions of two different compounds switch places. This type of reaction typically forms one or more products, which can also include precipitates, gases, or water. In the example of \[\mathrm{CuCl}_{2}(\mathrm{s}) + \mathrm{Na}_{2} \mathrm{SO}_{4}(\mathrm{aq}) \rightarrow \mathrm{CuSO}_{4}(\mathrm{aq}) + 2\mathrm{NaCl}(\mathrm{aq})\], a double displacement reaction takes place as the copper ions \((\mathrm{Cu}^{2+})\) from copper(II) chloride pair with sulfate ions \((\mathrm{SO}_{4}^{2-})\), while the sodium ions \((\mathrm{Na}^{+})\) pair with chloride ions \((\mathrm{Cl}^{-})\).

• The reactants must be soluble in water to allow the ions to disassociate and recombine.
• Observing new products helps confirm a double displacement reaction has occurred.
• This reaction type frequently results in at least one product that is insoluble in water.

Understanding double displacement reactions is essential for predicting the formation of new compounds in chemical reactions.

Balancing equations

Balancing a chemical equation is crucial to ensure it obeys the Law of Conservation of Mass. This law states that matter cannot be created or destroyed in a chemical reaction. Thus, each side of the equation must have the same number of atoms for every element involved. To balance a chemical equation, follow these steps:

• Write down the unbalanced equation.
• List the number of each type of atom for both reactants and products.
• Adjust coefficients to balance each type of atom on both sides.
• Confirm the atom count is equal in both reactants and products.

In the given equation \[\mathrm{CuCl}_{2}(\mathrm{s}) + \mathrm{Na}_{2} \mathrm{SO}_{4}(\mathrm{aq}) \rightarrow \mathrm{CuSO}_{4}(\mathrm{aq}) + 2\mathrm{NaCl}(\mathrm{aq})\], the coefficient "2" before \(\mathrm{NaCl}\) ensures the balance of chlorine and sodium atoms. Balancing equations is a fundamental skill in chemistry that ensures reactions are correctly represented.

Reactants and products

In any chemical reaction, reactants are the initial substances that undergo a change to form new substances called products. Understanding the nature of reactants and products helps in predicting the outcome of a reaction and writing balanced chemical equations. In our example,

• The reactants are copper(II) chloride \(\mathrm{CuCl}_{2}(\mathrm{s})\) and sodium sulfate \(\mathrm{Na}_{2}\mathrm{SO}_{4}(\mathrm{aq})\).
• The double displacement reaction transforms these reactants into products, which are copper(II) sulfate \(\mathrm{CuSO}_{4}(\mathrm{aq})\) and sodium chloride \(\mathrm{NaCl}(\mathrm{aq})\).

Identifying reactants and products is a key step in analyzing chemical equations.

• Reactants reside on the left side of a chemical equation.
• Products are found on the right side of the chemical equation.
• Understanding the solubility, state, and reactivity helps in predicting the products.

Reactants and products are a foundational concept in chemistry, crucial for understanding how substances transform during reactions.