CER Concepts - Lab 1

Sources of error
→ Mistakes or things that could mess up your experiment results.
Example: If your thermometer wasn’t calibrated, your temperature readings might be wrong.

Qualitative vs. Quantitative

• Qualitative = qualities (words). Example: “The flame turned green.”

• Quantitative = quantities (numbers). Example: “The flame temperature was 1,200°C.”

Selective precipitation as an analytical technique
→ When you add a chemical that makes only one specific substance form a solid (precipitate), while others stay dissolved. Scientists use this to separate or identify substances.

Relationship between solubility and temperature
→ Usually, solids dissolve better in hotter water (like sugar in tea). But gases dissolve better in colder water (that’s why soda goes flat faster when warm).

Flame tests as an analytical technique
→ Different elements give off different colors when burned in a flame. Example: Sodium makes yellow, copper makes green/blue, potassium makes purple. Scientists use this to identify metals.

Solubility rules
→ Shortcut rules to predict if a solid will dissolve in water or form a precipitate. Example: “All nitrates (NO₃⁻) dissolve in water” or “Most silver salts don’t dissolve, except silver nitrate.”