CHEM 1010 General Study Guide - Chapters 13 PDF

# CHEM 1010 General Study Guide - Chapters 13 ## Important Note: The exams will cover material from the textbook, lectures, and assignments. The best method to prepare for exams is to attend class, read the textbook, do the assignments, do extra problems at the end of the chapter (OWLv2 ASP and Mu...

# CHEM 1010 General Study Guide - Chapters 13 ## Important Note: The exams will cover material from the textbook, lectures, and assignments. The best method to prepare for exams is to attend class, read the textbook, do the assignments, do extra problems at the end of the chapter (OWLv2 ASP and Multimedia Activities), and seek help if you do not understand any aspect of the course. The posted lecture notes are only an outline of what is actually said in class. Anything said in class or in the text readings is a fair game for exams. Success in this course requires self-motivation and willingness to truly apply yourself. That is up to you! ## Chapter 13 - What describes an acid? - What describes a base? ## Acids-Bases Molecular Definitions ### Arrhenius - Acids produce hydrogen ions ($H^+$) in solution. - Bases produce hydroxide ions ($OH^-$) in solution. - But Arrhenius' definitions do not apply in all cases. ### Brønsted-Lowry - Broader definition - Works in solutions that do not contain water - Focuses on the transfer of protons ($H^+$ ions) - In the Brønsted-Lowry definition, acids are proton donors and bases are proton acceptors. ## $NH_3(g) + H_2O(l) \longrightarrow NH_4^+(aq) + OH^-(aq)$ - Which substance is acting as an acid? - Which is acting as a base? ## Conjugate Pairs In the reaction $H_2O + NH_3 \longrightarrow OH^- + NH_4^+$ - $H_2O$ and $OH^-$ constitute an acid/conjugate-base pair. - $NH_3$ and $NH_4^+$ constitute a base/conjugate-acid pair. ## Strong and weak acids ## Strong and weak bases ### 6 Strong Acids - $HCIO_4$: perchloric acid - $HCI$: hydrochloric acid - $HBr$: hydrobromic acid - $HI$: hydroiodic acid - $HNO_3$: nitric acid - $H_2SO_4$: sulfuric acid ### 6 Strong Bases - $LiOH$ : lithium hydroxide - $NaOH$ : sodium hydroxide - $KOH$ : potassium hydroxide - $Ca(OH)_2$ : calcium hydroxide - $Sr(OH)_2$ : strontium hydroxide - $Ba(OH)_2$ : barium hydroxide ## Acid-base reactions ## $pH$ -> $pH$ calculations ### $H_3O^+$ concentration - The acidity of a solution is normally specified by the concentration of $H_3O^+$ in moles per liter of solution, M. - Pure water has a $H_2O$ concentration of $1 \times 10^{-7} M$. $2H_2O \longrightarrow H_3O^+ + OH^-$ $[H_3O^+] = [OH^-] = 1 \times 10^{-7}M$ at 25 °C in pure water. ### Ion Product of Water - The product of the $H_3O^+$ and $OH^-$ concentrations is always the same number. - The number is called the ion product of water $K_w$ - $ [H_3O^+] \times [OH^-] = 1 \times 10^{-14} = K_w$ - Inversely proportional. ## Acidic and Basic Solutions ### Calculations $ [H^+] = \frac{1.0 \times 10^{-14}}{[OH^-]} $ $ [OH^-] = \frac{1.0 \times 10^{-14}}{[H^+]} $ ### Acidic and Basic Solutions - Neutral solutions - $[H_3O^+] = [OH^-] = 1 \times 10^{-7}$ $pH$ = 7 - Acidic solutions → $[H_3O^+] > [OH^-]$ $pH < 7$ - $[H_3O^+] > 1 \times 10^{-7};$ - $[OH^- ]<1 \times 10^{-7}$ - Basic solutions → $[H_3O^+] < [OH^-]$ $pH > 7$ - $[H_3O^+] < 1 \times 10^{-7};$ - $[OH^- ]>1 \times 10^{-7}$ ### Calculations - $pH= -log [H_3O^+]$ - $pOH = -log [OH^-]$ ### Neutral solutions - $[H_3O^+] = [OH^-]=1 \times 10^{-7}$ $pH$ = 7 - $[H_3O^+] \times [OH^-]=1 \times 10^{-14} = K_w$ ## The $pH$ Scale - The $pH$ scale measures how acidic or basic a solution is. - The $pH$ scale ranges from 0 to 14. - A $pH$ = 7 is neutral. - A $pH$ < 7 is acidic. - A $pH$ > 7 is basic. ## $pH + pOH = 14.00 $ ## Describing antacid action of Sodium Bicarbonate ($NaHCO_3$) and Sodium Carbonate ($Na_2CO_3$) with a chemical equation. ## Acid rain - acid rain effects - A diagram showing how acid rain is formed with arrows, chemical reactions, and written text. - A diagram showing the effects of acid rain and a diagram that shows how the clean air act amendments try to solve the issue.