Balance the equation in Figure 11.17 . If the bombardier...

Balance the equation in Figure $11.17 .$ If the bombardier beetle stores 100.0 $\mathrm{mg}$ of hydroquinone $\left(\mathrm{C}_{6} \mathrm{H}_{4}(\mathrm{OH})_{2}\right)$ along with 50.0 $\mathrm{mg}$ of hydrogen peroxide $\left(\mathrm{H}_{2} \mathrm{O}_{2}\right),$ what is the limiting reactant?

Balance the equation in Figure $11.17 .$ If the
bombardier beetle stores 100.0 $\mathrm{mg}$ of hydroquinone
$\left(\mathrm{C}_{6} \mathrm{H}_{4}(\mathrm{OH})_{2}\right)$ along with 50.0 $\mathrm{mg}$ of hydrogen peroxide $\left(\mathrm{H}_{2} \mathrm{O}_{2}\right),$ what is the limiting reactant?

Key Concepts

Limiting Reactant

The limiting reactant is the substance that is completely consumed in a chemical reaction, limiting the amount of product that can be formed. Determining the limiting reactant involves comparing the mole ratios of the reactants from the balanced equation to the available amounts, ensuring which one runs out first and thereby halting the reaction earlier than the other reactants.

Stoichiometry

Stoichiometry is the area of chemistry that involves calculating the quantitative relationships between reactants and products in a chemical reaction. This concept utilizes the balanced chemical equation to convert between units such as moles, mass, or particles, enabling chemists to determine the amounts of substances needed or produced.

Balancing Chemical Equations

Balancing chemical equations ensures that the law of conservation of mass is upheld during chemical reactions. It involves adjusting the coefficients of reactants and products so that the number of atoms of each element is the same on both sides of the equation, which is crucial for accurately applying stoichiometric calculations.

Mole Concept

The mole concept is a fundamental principle in chemistry that provides a bridge between the atomic scale and the macroscopic scale. It defines the mole as a specific number of entities (usually atoms or molecules) and is essential for converting between the mass of a substance and the number of particles, a key step in stoichiometric calculations.

Transcript

00:01 In this first part of the question, we need to balance the chemical equation for the reaction between hydroquinone and oxygenated water or hydrogen peroxide.

00:16 The formula that is given of hydroquinone and this reaction is in the figure provided is c6 h4 2 -ohish groups reacting with hydrogen peroxide giving rise to mesokinone whose formula is c6h402 plus water plus oxygen.

01:00 Now what you realize as you look at the figure is that these oh groups becomes ketone groups, which means that hydroquinone is getting oxidized to benzokinone.

01:22 Okay? so that's an oxidation reaction.

01:26 You also realize that hydrogen peroxide is getting oxidized and reduced.

01:35 It's getting reduced because the oxygen goes from negative 1 to negative 2 in water.

01:41 And it's also getting oxidized because the oxygen is going from negative 1 to 0.

01:46 In oxygen.

01:48 So we have two oxidation reactions taking place and one reduction reaction taking place.

01:56 This reaction takes place in let's assume an acidic environment because of the oh group that are attached to the benzene green which makes this oxen, this hydrogen acidic.

02:17 Okay? so we are going to first take care of the oxidation reactions and balance them as if they're happening in an acidic environment.

02:28 The first oxidation reaction is hydroquinone becoming benzokinin.

02:47 So we have six carbon, six carbon, six hydrogen, for hydrogen, therefore we need two hydrogens, ions.

03:02 And then we have two oxygens, two oxygens, two oxygens.

03:10 So, all we have to do is adding the electrons to balance the charges we have zero charge on the reactant to positive charge we need two negative charges okay this is the first of the two oxidation reactions the other oxidation reaction again is hydrogen peroxide getting oxidized to oxygen.

03:48 We have two hydrogen here.

03:51 We need to add two hydrogen ions here.

03:56 Two oxygen, two oxygen.

03:58 In order to balance the charges, we have zero here, two positive here.

04:04 We need to add two electrons here.

04:07 Okay? and now we add these two oxidation reactions to have one oxidation reaction.

04:21 We have hydroquinone plus hydrogen peroxide, producing benzokinin plus oxygen, plus four hydrogen ions, plus four electrons.

05:03 Now let's take care of the reduction reaction...