EXP 24

• Mixtures are composed of two or more components, which do not react with each other.
• Stoichiometry deals with mass relationships between reactants and products in chemical reactions.
• It is based on balanced equations and the mole concept.
• The mass of both reactants and the mass of both products will be calculated using only experimental mass measurements. This is called a gravimetric analysis.
• The percent composition of this mixture can be calculated from mass data by knowing the following five factors.

  1.The identity of the components of the mixture.

  2. The total mass of the mixture used for analysis.

  3. The identity of common products to which both components can be converted.

  4. The two balanced chemical equations that describe the reactions used to convert each component to the common products.

  5. The mass of one of the products from the above reactions.
• A mixture of NaHCO3 and Na2CO3 reacts with hydrochloric acid solution to produce three common products, sodium chloride, carbon dioxide and water
• After boiling off the water and any unreacted excess acid, the remaining residue is solid which can easily be dried and weighed.