General Chemistry - Stoichiometry

Explore Avogadro's number and the mole to connect atomic mass units to grams, learn molar mass, and apply conversion factors for stoichiometric calculations.

Convert a 76.3 g calcium sample to moles using molar mass 40.078 g/mol, then use Avogadro's number to find the number of calcium atoms and the mass per atom.

Compute the number of atoms in two samples by converting grams to moles using molar masses and Avogadro's number, comparing hydrogen and nitrogen samples.

Sum atomic masses to obtain molecular mass, as in H2O's 18.02 amu, which equals molar mass. Also cover mass spectrometry for accurate atomic and molecular mass determination.

Compute molecular masses by multiplying each element’s atomic mass by its atom count in a formula, then use molar mass as a conversion factor to convert grams to moles.

Calculate hydrogen atoms in a 74.5 g caffeine sample by determining caffeine's molar mass, converting mass to moles, using the formula for hydrogen, then converting to atoms with Avogadro's number.

Learn to calculate percent composition by mass from a formula and derive empirical and molecular formulas using molar masses and mass percentages.

In example seven, compute the percent composition of nitrogen in four fertilizers using molar masses and nitrogen's atomic mass (14), showing F three as the richest nitrogen source.

Determine the oxygen content and empirical formula from mass percent data in stoichiometry, using a 100 g sample, then derive C2H3NO5 and identify the molecular formula.

Balance chemical equations to conserve mass by placing coefficients so the same number of each atom appears on both sides; illustrate with hydrogen, oxygen, and methane combustion.

Balance chemical equations using a step-by-step procedure that starts with identifying the most complex substance and assigns the correct coefficients, as shown for the two examples.

Master stoichiometry using the mole method: convert any reactant or product to moles using molar mass, use the balanced equation for mole ratios, then convert moles back to mass.

Balance the fermentation equation, convert glucose to moles, apply the 1:2 mole ratio to ethanol, and convert back to grams to obtain about 179.2 g ethanol from 350 g glucose.

Balance the decomposition of baking soda to carbon dioxide and sodium carbonate, then calculate the mass of baking soda needed to produce 26.8 g of CO2 using stoichiometry.

Explore limiting reactant concept in stoichiometry, using a dance-floor analogy to show how the limiting reactant sets product, how excess reactant remains, and how to identify it using coefficients.

Explore reaction yield by comparing theoretical yield with actual yield, explain factors like reversibility and recovery losses, and show how percent yield can be improved by adjusting temperature or pressure.

Compute the theoretical yield and percent yield of vanadium from a balanced V2O5 and Ca reaction, identifying the limiting reactant using molar masses and the actual yield.