CHEM 1A Lecture Notes - Lecture 7: Equilibrium Point, Electrolyte, Electric Potential

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indigoworm709

13 Oct 2018

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UCSB

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Chemistry and Biochemistry

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CHEM 1A

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BERNT C M

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CHEM 1A Lecture 6: Fall 2018

CHEM 1A Lecture Notes - Lecture 7: Equilibrium Point, Electrolyte, Electric Potential

CHEM 1A Lecture 8: Fall 2018

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Acid: substance that increases amount of h + ions in solution (bronsted-lowry definition) This reaction represents the dissociation of hcl into its ions. Note: some acids (like ammonium) doesn"t follow the naming convention, + , acetic acid, most other acids so be careful! The sign means it"s a equilibrium reaction, meaning the reaction can happen either way till it reach an equilibrium point. Even though 100% of h 2 so 4 dissociates in water, which makes it a strong acid, not all of hso 4 . *a chart of strong and weak acids will be given for the exam. Some acids dissociate to a small extent in water not 100% of acetic acid will dissociate in water ( https://study. com/academy/lesson/what-is-acetate-definition-properties-formula. html ) Recall that only the h attached to o is able to dissociate, therefore considered acidic. Bases: substance that increase amount of oh - ions in solution. Naoh, koh, lioh, ca(oh) 2 , and other (group 1 or 2)oh.

Related Questions

Part A A fuel cell differs from a battery because the current is being generated from a reduction-oxidation (redox) reaction in which the reactant is consumed. A classic example of a fuel cell is the phosphoric acid fuel cell (PAFC), which have been used in stationary power generators, buses, and even submarines. Fuel cells require an electrolyte (similar to batteries) to carry electrically charged species between the electrodes, and a PAFC utilizes phosphoric acid (H3PO4) as its electrolyte. Phosphoric acid has three acidic protons that can dissociate in water, as highlighted in red here: H3PO4. However, it is considered a weak acid because some of the acid will remain in molecular form when dissolved in water. Write the complete ionic equation that depicts the dissociation of the first proton for the weak acid phosphoric acid (H3PO4). Make certain you include all charges for any ions produced. Express you answer as a chemical equation including phases. Titrations as analytical neutralization reactions Neutralization reactions can occur between any combination of weak/strong acids and bases. When we want to determine the concentration of a base in solution, we can apply the concept of neutralization by reacting the base with a known amount of an acid in the presence of an indicator (a compound that changes color depending on the pH). This method of determining the concentration of a base is called acid-base titration, and it can also be used to determine the concentration of an acid by titrating it with a known amount of base. A common acid to use for titrations is potassium hydrogen phthalate (written as KHP or KHPh; do not confuse the P for phosphorus). The reason KHP is common is because it is solid at room temperature, and we can accurately mass the amount that is added to solution. As a soluble salt, KHP completely dissociates to form a potassium ion (K+) and an acidic hydrogen phthalate ion (HPâ), which is a weak acid that has only one acidic hydrogen. This ionization is depicted below. KHP(s) â K+(aq)+HPâ(aq) Although ionization (the formation of ions) occurs as a result of acid dissociation for most weak acids, KHP ionizes before acid dissociation occurs. In other words, HPâ is a weak acid ion. Part C If you wanted to determine how much KOH (potassium hydroxide; a strong base) was dissolved in water, you could titrate it with a known amount of KHP (potassium hydrogen phthalate; a weak acid) until a color change indicates that the base is completely neutralized. The molecular equation below depicts this neutralization reaction. KHP(aq)+KOH(aq)âK2P(aq)+H2O(l) Write the net ionic equation that depicts the neutralization of the base by potassium hydrogen phthalate. Instead of using the entire chemical formula of phthalate, use HPâ to represent the acidic hydrogen phthalate ion and P2â to represent the phthalate ion. Express your answer as a net ionic equation including phases.

.ill AT&T 9:44 AM Back Chem1B-W18-Homework5.pdf [1] This homework assignmenté·due at the begining of class on March 9., 2018, write your answers on a separate piece of paper, and show your work to receive credt Protiem 1 What distinguishes a strong acid from a weak acid7 What distinguishes a strong base from a weak base? Write out examples of the proton-transfer reaction for each as well as the equilibrium expression (K or Ko) tor each ? Wrtie equations Probiem 2 In class we dscussed e autoionization of water, What is an for the autoionization reactions for H-O and H SO Assume that both are pure iquids Problem 3 In class on Friday, we calculated the [HO-1 and [OH in stomach acid at pH 1.5 The average volume of an adult human stomach is 1L. How many H0 ions are present in a human stomach i&the pH is 2.0? How many OH- ions? man body temperatre). Problem4 any equlbnum constant. Min changes with temperature. At 37 â the pH of waner is 6.80. Caloulate the following for pure water at this temperature: b) IOH1 Problems whais a con ate acid-base pair? What is the relationship between the two members of pair? Prettem.6 Draw a Lewis structure ot each of thy tolowing acids. Then, wte balanced aciddssociaton reactions and equibrium expressions for each in water. a) Formic acid, HCOOH b) Chloric acid, HCIO, c) Dihydrogen arsenate, H As0 Probiem Z Dihydrogen arsenate is an ampiprotie substance, meaning tcan both accept and donane a proton Draw Lewis structures of the conjugate acid and the conjugate base of dihydrogen arsenate. Write the balanced base-dissociation reaction and equiibrium expression of dihydrogen arsenate in water Paatina successivo K.'s for polyprotic acids decrease. For thÃ© polyproc phosphoric acid. HAo, K., 7.2 x10. KA6.3 x 10, Ka 4.2 x 10- Draw Lewis structures of each of the species involwed in each acid- dissociation roactonãWhy d0the K.'s decrease for each successi e deprotaraton? Protiem 2 Hypochionous acid, HCIO, has a pka ol 7.54. What are the [Hs0-]. pH. [CO1 and [HCIO] in a 0.115 M solution of HCI0? Problema in a 0 735 M solution a weak acid is 12 5% dssoc ated. a) Calculatemo-1, pHÂ·[OH 1, and pH of the solution. b) Calculate Ka of the acid Problemi! Acetyisaleyic acid (asprin, structure shown to the right). HCæ¤:O4, is the most widely used pain reliever and tever reducer. Find the pH of 0.018 M aqueous aspirin at body temperature (K.: 3.6 x 104 at 37Â°C). Problem12 whyé·aqueous NaF basic but aqueous NaCl neutral? Chit consider the reaction of each anion with water 1 of 1 Previous Dashboard Calendar To Do Notifications Inbox

CHEM 1A Lecture Notes - Lecture 7: Equilibrium Point, Electrolyte, Electric Potential

CHEM 1A Lecture 6: Fall 2018

CHEM 1A Lecture Notes - Lecture 7: Equilibrium Point, Electrolyte, Electric Potential

CHEM 1A Lecture 8: Fall 2018

Document Summary

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