Your Final Grade 1st Quarter – 20% 2nd Quarter – 20% 3rd Quarter – 20% 4th Quarter - 20% Final Exam – 20% (SGM – 15%, Final exam 5%)

What’s on the final? Chapter 9 - Stoichiometry The four types of stoichiometric conversions Limiting reactant calculations Chapter 11 – Gas Laws Combined Gas Law, Ideal Gas Law You need to know STP and formulas Acids and Bases notes You should also know: Metric prefixes and conversions Significant figures – identify and calculate using them

Preparing for the final Wednesday– Notes on Acids and Bases Thursday– Review assignment with sub. Friday – pH Indicator Lab Monday – 4th period and 6th period take exam Tuesday – 5th and 7th period take exam

Acids and Bases

Definitions: Acid - a substance that produces hydrogen ions, H+, in an aqueous solution; Base - a substance that produces hydroxide ions, OH-, in an aqueous solution.

Acids Taste sour (do NOT taste a chemical to test this) React with certain metals (Zn, Fe, Mg, etc.) to produce hydrogen gas Changes litmus paper red Conduct electricity React with bases to form salts and water

Bases Taste bitter Feel slippery or soapy Conduct electricity Changes litmus paper blue React with acids to form salts and water

Monoprotic and polyprotic Acids Monoprotic acid – can donate only one hydrogen ion per molecule Diprotic acids – can donate two hydrogen ions per molecule Triprotic acids – can donate three hyrdrogen ions per molecule

Reaction of acids and bases with water: Acids and bases form ions in solution: Acids form H+ in aqueous solutions ex: HCl(aq) H+(aq) + Cl-(aq) Bases form OH- in aqueous solutions ex: NaOH(aq) Na+(aq) + OH-(aq)

Strengths of acids and bases A strong acid is ionizes completely in aqueous solutions; A weak acid releases few hydrogen ions in aqueous solutions. As with acids, the strength of a base depends on the extent to which it dissociates, or adds hydroxide ions, to the solution.

Neutralization and Salts Neutralization - one type of double replacement reaction Acid + Base Salt + water example: HCl(aq) + NaOH(aq) NaCl(aq) + H2O(l)

pH Scale pH is a measurement of the concentration of hydrogen ions (H+) in the solution. The pH scale goes from 0 to 14 pH 7 is neutral Anything less than 7 is acidic, and anything greater than 7 is basic Common examples: Tomatoes 4.0 – 4.4 Apples 2.9 – 3.3 Gastric juice 1.0 – 3.0 Blood 7.3 - 7.5 Saliva 6.5 – 7.5 Lemons 1.8 – 2.4

Some acids are useful in industry Sulfuric acid (H2SO4) Most commonly produced industrial chemical in the world. Used in automobile batteries. Hydrochloric Acid (HCl) Produced in stomach to aid in digestion; Used in multiple industrial processes; Called muriatic acid in hardware stores.

Nitric Acid (HNO3) This acid has a suffocating odor, stains skin, and can cause serious burns; Used in making explosives. Phosphoric Acid (H3PO4) Mostly used in fertilizer production; Has a pleasant but sour taste and is not toxic and is used as a flavoring agent Acetic Acid (CH3COOH) Vinegar

https://All About That Base Simpsons Acid Rain