Lecture : Gen Chem Lecture-4
Document Summary
Atomic and formula: actual yield=theoretical, as reactants are converted to products we observe, color change, precipitate formation, gas evolution, heat absorption or evolution. Chemical evidence may be necessary: write the reaction masses. Chemical equations: mole ratio or stoichiometric factor is a central conversion factor. It is important to include units and to work from a balanced chemical equation when solving stoichiometry problems. chemical. Chemical reactions in solution using symbols: balance the chemical equation. Balancing equations: an equation can be balanced only by adjusting the coefficients of formulas, never introduce extraneous atoms to balance, never change a formula for the purpose of balancing an equation. Balancing equation strategy: balance elements that occur in only one compound on each side first, balance free elements last, balance unchanged polyatomics (or other groups of atoms) as groups. Fractional coefficients are acceptable and can be cleared at the end by multiplication. Close contact between atoms, ions, and molecules necessary for a reaction to occur.
