Chemistry Exam - Unit 3 & 4

Mole

6.02 × 10²³ of any chemical unit (atoms, molecules, ions, others)

Aqueous Solution

solution where the solvent is water

Precipitate

insoluble solids that emerges from liquid solution

Factors affecting solubility of gases, liquids and solids

• solubility of SOLIDS INCREASE as temperature increases

• solubility of LIQUIDS INCREASE as temperature increases

• solubility of GASES DECREASE as temperature increases

Saturated Solution

has the same concentration as the solubility

Unsaturated Solution

has less concentration than the solubility

Litmus paper

RED litmus paper turns BLUE in a BASES

BLUE litmus paper turns RED in ACID

Phenolphthalein Indicator

turns PINK in a BASE, remaind CLEAR in an ACID

Probe/pH Meter

provides a more accurate pH reading

Properties of acid (and examples)

pH less than 7, sour, non-slippery, irritate skin, conducts electricity in aq solution

• lemon, oranges, tomatoes

Properties of bases (and example)

pH more than 7, slippery, irritates skin, conducts electricity in aq solution

• baking soda, cleaning supplies, soap

limiting reagent

reactant that is consumed completely

excess reagent

reactant that is not fully consumed

empirical formula

formula that shows the SIMPLEST WHOLE-NUMBER of elements in a compound

molecular formula

a formula that shows the element symbols and EXACT NUMBER OF EACH TYPE OF ATOM in a molecular compound

titrant

standard solution of an acurately known concentration

stock solution

a concentrated solution of a substance that is used to prepare less concentrated solutions or for chemical reactions