Question

Solid zinc is added to an aqueous solution containing dissolved hydrogen chloride to produce gaseous hydrogen that bubbles out of the solution and zinc chloride that remains dissolved in the water. Write the unbalanced chemical equation for this process.

Short answer

The unbalanced chemical equation for the given reaction is: \(Zn + HCl \rightarrow H_2 + ZnCl_2\).

Step-by-step solution

Identify the reactants

In the given reaction, solid zinc (Zn) and aqueous hydrogen chloride (HCl) are the reactants.

Identify the products

The products of the given reaction are gaseous hydrogen (H2) and aqueous zinc chloride (ZnCl2).

Write the unbalanced chemical equation

Using the information from Steps 1 and 2, we can write the unbalanced chemical equation as follows: \(Zn + HCl \rightarrow H_2 + ZnCl_2\) This is the unbalanced chemical equation for the given reaction.

Key concepts

Chemical Reactions

Understanding chemical reactions is fundamental in the study of chemistry. A chemical reaction is a process that leads to the transformation of one set of chemical substances to another. During a chemical reaction, the molecular structure of the substances changes through the breaking and forming of chemical bonds. This results in the conversion of reactants into products with distinct properties.

For instance, when solid zinc reacts with an aqueous solution of hydrogen chloride, we witness a chemical reaction. The reactants here, solid zinc (Zn) and hydrogen chloride (HCl), undergo a transformation leading to the creation of new substances: gaseous hydrogen (H₂) and zinc chloride (ZnCl₂) in solution. It's essential to note that the physical state of the substances often plays a critical role in how the reaction proceeds.

Reactants and Products

In every chemical equation, we differentiate between reactants and products. The reactants are the starting materials, which participate in the reaction to produce something new. On the flip side, the products are the outcome of the reaction.

In our original exercise, the solid zinc (Zn) and aqueous hydrogen chloride (HCl) are the reactants, as they are the starting substances before the reaction occurs. After the reaction, we are left with gaseous hydrogen (H₂) and aqueous zinc chloride (ZnCl₂), which are the products of the reaction. Identifying reactants and products correctly is crucial for writing both balanced and unbalanced chemical equations.

Stoichiometry

Stoichiometry is the quantitative study of reactants and products in a chemical reaction. It's a segment of chemistry that involves using relationships between reactants and products to determine various quantitative data points, such as how much reactant is needed to produce a certain amount of product.

When dealing with an unbalanced chemical equation like the one from our exercise, stoichiometry helps us calculate the correct proportions of reactants and products. The equation provided, \(Zn + HCl \rightarrow H_2 + ZnCl_2\), is unbalanced, which means that the number of atoms for each element is not equal on both sides of the arrow. Balancing this equation is necessary for the law of conservation of mass, which states that matter cannot be created or destroyed in an isolated system. Stoichiometry not only helps balance equations but also can be used to calculate the yields of a reaction, determine limiting reactants, and so much more, making it an integral part of understanding chemical reactions fully.