Question

Give the balanced equation for each of the following chemical reactions: a. Glucose $\left({\mathrm{C}}_6{\mathrm{H}}_{12}{\mathrm{O}}_6\right)$ reacts with oxygen gas to produce gaseous carbon dioxide and water vapor. b. Solid iron(III) sulfide reacts with gaseous hydrogen chloride to form solid iron(III) chloride and hydrogen sulfide gas. c. Carbon disulfide liquid reacts with ammonia gas to produce hydrogen sulfide gas and solid ammonium thiocyanate $\left({\mathrm{NH}}_4\mathrm{SCN}\right).$

Short answer

a. The balanced equation for the reaction between glucose and oxygen gas is: $$C_6{H}_{12}{O}_6+6O_2\to 6C{O}_2+6H_{2}O$$ b. The balanced equation for the reaction between iron(III) sulfide and hydrogen chloride is: $$F{e}_2{S}_3+6HCl\to 2FeC{l}_3+3H_{2}S$$ c. The balanced equation for the reaction between carbon disulfide and ammonia gas is: $$C{S}_2+2N{H}_3\to 2H_{2}S+N{H}_{4}SCN$$

Step-by-step solution

a. Balancing the equation for the reaction between glucose and oxygen gas

To balance the chemical equation, we need to make sure that there are equal numbers of each atom on both sides of the equation. Let's write the unbalanced equation first: $$C_6{H}_{12}{O}_6+O_2\to C{O}_2+H_{2}O$$ Next, let's balance the equation by adjusting the coefficients. For each atom, count the number on both sides and adjust the coefficients accordingly: - Carbon (C): There are 6 carbon atoms in glucose, and the product side has only 1 carbon atom in CO2. So, we need 6 CO2 molecules to balance the carbon atoms: $$C_6{H}_{12}{O}_6+O_2\to 6C{O}_2+H_{2}O$$ - Hydrogen (H): There are 12 hydrogen atoms in glucose, and 2 hydrogen atoms in a water molecule. So, we need 6 water molecules to balance the hydrogen atoms: $$C_6{H}_{12}{O}_6+O_2\to 6C{O}_2+6H_{2}O$$ - Oxygen (O): There are 6 oxygen atoms in glucose and 2 in a molecule of oxygen gas. In the products, we have 12 oxygen atoms in CO2 and 6 in water. We need 6 O2 molecules to complete the balance: $$C_6{H}_{12}{O}_6+6O_2\to 6C{O}_2+6H_{2}O$$ So, the balanced equation for the reaction between glucose and oxygen gas is: $$C_6{H}_{12}{O}_6+6O_2\to 6C{O}_2+6H_{2}O$$

b. Balancing the equation for the reaction between iron(III) sulfide and hydrogen chloride

First, write the unbalanced equation: $$F{e}_2{S}_3+HCl\to FeC{l}_3+H_{2}S$$ Now, we'll balance each atom: - Iron (Fe): There are 2 iron atoms in iron(III) sulfide, and only 1 in iron(III) chloride. So, we need 2 iron(III) chloride molecules to balance the iron atoms: $$F{e}_2{S}_3+HCl\to 2FeC{l}_3+H_{2}S$$ - Sulfur (S): There are 3 sulfur atoms in iron(III) sulfide, and 1 in hydrogen sulfide. So, we need 3 hydrogen sulfide molecules to balance the sulfur atoms: $$F{e}_2{S}_3+HCl\to 2FeC{l}_3+3H_{2}S$$ - Hydrogen (H) and Chlorine (Cl): We have 2 chlorine atoms in 2 molecules of FeCl3 and 6 hydrogen atoms in 3 molecules of H2S, which means we need 6 hydrogen chloride molecules to balance the equation: $$F{e}_2{S}_3+6HCl\to 2FeC{l}_3+3H_{2}S$$ The balanced equation for the reaction between iron(III) sulfide and hydrogen chloride is: $$F{e}_2{S}_3+6HCl\to 2FeC{l}_3+3H_{2}S$$

c. Balancing the equation for the reaction between carbon disulfide and ammonia gas

Start by writing the unbalanced equation: $$C{S}_2+N{H}_3\to H_{2}S+N{H}_{4}SCN$$ Now, balance the equation atom by atom: - Carbon (C): There is 1 carbon atom in both carbon disulfide and ammonium thiocyanate, so it's balanced as is. - Sulfur (S): There are 2 sulfur atoms in carbon disulfide, 1 in hydrogen sulfide, and 1 in ammonium thiocyanate. So, we need 2 hydrogen sulfide molecules to balance sulfur atoms: $$C{S}_2+N{H}_3\to 2H_{2}S+N{H}_{4}SCN$$ - Hydrogen (H) and Nitrogen (N): There are 6 hydrogen atoms in 2 molecules of H2S and 3 in NH3, and 1 nitrogen atom in both NH3 and NH4SCN. Therefore, we need 2 ammonia molecules to balance hydrogen and nitrogen: $$C{S}_2+2N{H}_3\to 2H_{2}S+N{H}_{4}SCN$$ The balanced equation for the reaction between carbon disulfide and ammonia gas is: $$C{S}_2+2N{H}_3\to 2H_{2}S+N{H}_{4}SCN$$

Key concepts

Balancing Chemical Reactions

Balancing chemical reactions is like solving a puzzle where you want the pieces to match perfectly on both sides. The key principle is that the number of atoms for each element remain the same before and after the reaction. When you balance a chemical equation, you adjust coefficients to ensure that all atoms are equally represented on both sides. For instance, if a reaction starts with six carbon atoms, it must end with six carbon atoms. This ensures that mass and energy are conserved. Balancing reactions helps us understand the proportions in which reactants combine to form products, a fundamental concept in chemistry.

Stoichiometry

Stoichiometry is the study of quantitative relationships in chemical reactions. It tells us how much of each substance is involved in a reaction. Understanding stoichiometry helps chemists determine how much of a reactant is required to fully react with another or how much product is expected. By using balanced chemical equations, stoichiometry allows us to make these calculations. For example, if a balanced equation indicates that 1 mole of a substance reacts with 2 moles of another, stoichiometry helps calculate the exact amounts needed. It's like a recipe that specifies the right proportions for a perfect dish. Understanding this concept is essential for making predictions about reaction yields and requirements.

Reaction Equations

Reaction equations are symbolic representations of chemical reactions. They use symbols and formulas to display the reactants and products involved in a chemical transformation. A typical reaction equation includes coefficients that balance the equation, indicating the relative amounts of each reactant and product. For example, the equation $C_6{H}_{12}{O}_6+6O_2\to 6C{O}_2+6H_{2}O$ represents the combustion of glucose, where each molecule of glucose reacts with six oxygen molecules to form six carbon dioxide and six water molecules. Reaction equations provide a clear and concise way to describe chemical changes and are essential tools for chemists to communicate reaction processes.

Chemical Reactions

Chemical reactions involve the transformation of substances into different substances through rearrangement of atoms. They occur everywhere around us, from digesting food to industrial manufacturing. During a chemical reaction, bonds between atoms are broken and new bonds are formed, resulting in new substances with different properties. Chemical reactions are often accompanied by energy changes, such as heat released or absorbed. They can be categorized into different types, such as synthesis, decomposition, single replacement, and double replacement. Understanding chemical reactions is crucial for explaining how substances interact and change, providing insights into chemical processes and applications.