Question

Consider the balanced equation $$ 2 \mathrm{Fe}\left(\mathrm{NO}_{3}\right)_{3}+3 \mathrm{Na}_{2} \mathrm{CO}_{3} \longrightarrow \mathrm{Fe}_{2}\left(\mathrm{CO}_{3}\right)_{3}+6 \mathrm{NaNO}_{3} $$ (a) How many atoms of \(\mathrm{Na}\) are on each side of the equation? (b) How many atoms of \(\mathrm{C}\) are on each side of the equation? (c) How many atoms of \(\mathrm{O}\) are on each side of the equation? (d) How many atoms of Fe are on each side of the equation?

Short answer

After reviewing the equation, there should be an equal number of Na and C atoms on both sides, which are 6 and 3 respectively, but there's an imbalance in O atoms, with 21 on the reactants side and 27 on the products side. There are 2 Fe atoms on each side as well. Oxygen imbalance suggests an error in the given chemical equation.

Step-by-step solution

Identify Atoms of Sodium (Na)

First, count the number of sodium atoms on both sides of the equation. On the reactant side, there are 3 molecules of Na2CO3, each containing 2 Na atoms, amounting to a total of 3 * 2 = 6 Na atoms. On the product side, there are 6 molecules of NaNO3, each with 1 Na atom, resulting in a total of 6 * 1 = 6 Na atoms.

Identify Atoms of Carbon (C)

Next, count the number of carbon atoms on both sides of the equation. On the reactant side, there are 3 molecules of Na2CO3, each with 1 C atom, which totals 3 * 1 = 3 C atoms. On the product side, there is only 1 molecule of Fe2(CO3)3, and it contains 3 C atoms. Thus, there are a total of 1 * 3 = 3 C atoms.

Identify Atoms of Oxygen (O)

Then, count the number of oxygen atoms on both sides of the equation. On the reactant side, there are 6 O atoms in each Fe(NO3)3 molecule times 2 equals 12 O atoms from Fe(NO3)3, and 3 O atoms in each Na2CO3 molecule times 3 equals 9 O atoms from Na2CO3, giving a total of 12 + 9 = 21 O atoms. On the product side, there are 3 O atoms in each CO3 group times 3 equals 9 O atoms from Fe2(CO3)3, and 3 O atoms in each NaNO3 molecule times 6 equals 18 O atoms from NaNO3, totaling 9 + 18 = 27 O atoms. Notice there appears to be an error in the balance of oxygen atoms.

Identify Atoms of Iron (Fe)

Finally, count the number of iron atoms. On the reactant side, there are 2 Fe atoms within 2 Fe(NO3)3 molecules, which equals 2 Fe atoms. On the product side, there is 1 molecule of Fe2(CO3)3, which contains 2 Fe atoms.

Analyze Oxygen Imbalance

It appears that the number of oxygen atoms in the original equation is unbalanced, with 21 on the reactants side and 27 on the products side. That means we need to modify the exercise's original given equation to correct the oxygen count.

Key concepts

Stoichiometry

Stoichiometry is a section of chemistry that involves calculating the relative quantities of reactants and products involved in a chemical reaction using the mole concept. It is grounded in the law of conservation of mass where the total mass of all substances in a reaction must remain constant. Therefore, stoichiometry helps in predicting how much product will form from a given amount of reactant, or how much reactant is needed to create a desired amount of product. To perform stoichiometry calculations, one must first have a balanced chemical equation, which serves as a recipe telling you the proportion of each substance involved.

Chemical Reactions

Chemical reactions are processes where substances, known as reactants, transform into new substances, called products. These transformations involve the breaking and forming of chemical bonds, leading to changes in the composition and properties of the substances involved. The notation of chemical reactions is done through chemical equations that illustrate the reactants and products, often indicating the physical state of these substances, and the conditions under which the reaction occurs. Balancing chemical equations is crucial as it ensures that the reaction adheres to the conservation of mass and atoms, reflecting the stoichiometry of the process.

Atom Counting

Atom counting is a fundamental practice in balancing chemical equations. It involves tallying the number of atoms of each element present in the reactants and products to check the balance. In the given exercise, atom counting is executed methodically for each element to verify if the chemical equation is balanced. The identified discrepancy in oxygen atoms indicates that the original equation provided was imbalanced, a critical observation step in the process of chemical analysis. It is essential to ensure that the same number of each type of atom is present on both sides of the equation to confirm that it abides by the laws of conservation of mass and atoms.

Mole Concept

The mole concept is pivotal in chemistry for it allows chemists to count particles by weighing them. A mole represents Avogadro's number (\(6.022 \times 10^{23}\) particles) of any substance. The mole concept connects the microscale of atoms and molecules to the macroscale grams that we can measure in the laboratory. It is the bridge between the number of atoms and the mass of a substance. In stoichiometry, the mole concept enables the conversion from moles of one substance to moles of another using the balanced chemical equation, which shows the ratio of moles of reactants to products involved in the reaction.