Stoichometry
what is stoichiometry?
a method for predicting or analyzing the quantities of reactants and products within a reaction
What are some assumptions made about reactions?
1) all reactions are spontaneous
2) reactions are fast
3) reactions are quantitative
4) reactions are stoichiometric
Quantitative vs Qualitative
qualitative analysis - identification or confirming the presence of a certain substance through observation
quantitative - determining the quality of the substance present
What are the techniques of qualitative analysis?
1) solution color
2) flame color test
3) selective precipitation
How is solution color a test?
when ions dissolve in water they will sometimes impart color, the concentration of the ion will determine the color
Can be quantitative - a spectrometer shines a light beam through a solution and records how much light is absorbed
How is flame color a test?
- ions impart a specific color to flame
- test for the presence of metallic ions is to dip a nichrome wire in solution and set it on fire
Formation of a precipitate a test?
during a double replacement reaction, a precipitate may form, in which case this indicates a reaction has taken place
However, in stoichiometry you can determine the ions in solution by adding specific ions to induce precipitates