Pure oxygen was first made by heating mercury(II) oxide: HgO --> (heat) Hg + O2 Unbalanced (a) Balance the equation. (b) How many grams of mercury and how many grams of oxygen are formed from 45.5 g of HgO? (c) How many grams of HgO would you need to obtain 33.3 g of O2

Verified step by step guidance

1. Step 1: Balance the chemical equation. The balanced equation for the reaction is 2HgO --> 2Hg + O2. This is done by ensuring that the number of atoms for each element is the same on both sides of the equation.
2. Step 2: For part (b), use the balanced equation to determine the stoichiometric ratio between HgO and Hg, and HgO and O2. From the balanced equation, we can see that 2 moles of HgO produce 2 moles of Hg and 1 mole of O2.
3. Step 3: Convert the given mass of HgO to moles using its molar mass (216.59 g/mol). Then, use the stoichiometric ratios to calculate the moles of Hg and O2 produced.
4. Step 4: Convert the moles of Hg and O2 to grams using their molar masses (Hg = 200.59 g/mol, O2 = 32.00 g/mol).
5. Step 5: For part (c), convert the given mass of O2 to moles using its molar mass. Then, use the stoichiometric ratio from the balanced equation to calculate the moles of HgO needed. Finally, convert the moles of HgO to grams using its molar mass.

Key Concepts

Balancing Chemical Equations

Balancing chemical equations involves ensuring that the number of atoms of each element is the same on both sides of the equation. This is based on the law of conservation of mass, which states that matter cannot be created or destroyed in a chemical reaction. To balance an equation, coefficients are adjusted in front of the chemical formulas to achieve equal atom counts.

Stoichiometry

Stoichiometry is the calculation of reactants and products in chemical reactions based on balanced equations. It allows for the determination of the amounts of substances consumed and produced, using mole ratios derived from the coefficients in the balanced equation. This concept is essential for converting between grams and moles, facilitating the calculation of how much of each substance is involved in a reaction.

Molar Mass

Molar mass is the mass of one mole of a substance, typically expressed in grams per mole (g/mol). It is calculated by summing the atomic masses of all atoms in a molecule. Understanding molar mass is crucial for converting between the mass of a substance and the number of moles, which is necessary for stoichiometric calculations in chemical reactions.