CHEM1101 Study Guide - Midterm Guide: Equivalence Point, Stoichiometry, Titration

을 Secure! https://session.masteringchemistry.com/myct/itemview?assignmentProblemiD-96111490 Intro to Acids and Bases Item 6 6 of 15> ▼ Part B By the Brønsted-Lowry definition, acids are proton donors and bases are proton acceptors. By the Lewis definition, acids are electron-pair acceptors, and bases are electron-pair donors. For bases, the two definitions are equivalent such that al Lewis bases are Bronsted-Lowry bases and vice versa. However, it is possible to have a Lewis acid that is not a Brønsted-Lowry acid. This is because Lewis acids include molecules and cations that have a vacant valence orbital, regardless of whether they have a proton to donate. Common examples of Lewis acids (that are not Bronsted- Lowry acids) are metal ions, such as A and Cu2+. The following is an example of a Lewis acid-base reaction: Classify each of the following as a Lewis acid or a Lewis base. Drag the appropriate items to their respective bins View Available Hint(s) Reset Help Cu2 +4NH+Cu(NH NHs donates the electron pair to Cu2 Therefore, NH3 is a Lewis base, and Cu2 is a Lewis acid. Lewis acids Lewis bases Submit Part C In the following pair, which species would you expect to be the stronger Lewis acid?

Adding a Strong Acid to a Buffer |〈 4014 Constants Periodic Table Part A Learning Goal To understand how buffers use reserves of conjugate acid and conjugate base to counteract the effects of acid or base addition on pH A beaker with 1.00x102 mL of an acetic acid buffer with a pH of 5.000 is sitting on a benchtop. The total molarity of acid and conjugate base in this buffer is 0.100 M. A student adds 4.40 mL of a 0.430 MHCl solution to the beaker. How much will the pH change? The pKa of acetic acid is 4.740 A buffer is a mixture of a conjugate acid-base pair In other words, it is a solution that contains a weak acid and its conjugate base, or a weak base and its conjugate acid. For example, an acetic acid buffer consists of acetic acid, CH3 COOH, and its conjugate base, the acetate ion CH3 COO. Because ions cannot simply be added to a solution, the conjugate base sodium acetate NaCH3 COO) Express your answer numerically to two decimal places. Use a minus (- ) sign if the pH has decreased. View Available Hint(s) is added in a salt form (e.g., Buffers work because the conjugate acid-base pair work together to neutralize the addition of Hor OH ions. Thus, for example, if H ions are added to the acetate buffer described above, they will be largely removed from solution by the reaction of H+ with the conjugate base ApH- Submit H' + CH3COO→CH3COOH

Adding a strong Acid to a Buffer Part A Learning Goal : A beaker with 145 mL of an acetic acid buffer with a pH of 5,000 is sitting on a benchtop. The total molarity of acid and conjugate base in this buffer is 0.100 M. A student adds 8.60 mL of a 0.320 M HC1 solution to the beakerHow much will the pH change? The pK, of acetic acid is 4.740. To understand how buffers use reserves of conjugate acid and conjugate base to counteract the effects of acid or base addition on pH Express your answer numerically to two decimal places. Use a minus (-) sign if the pH has decreased. Hints A buffer is a mixture of a conjugate acid-base pair. In other words, it is a solution that contains a weak acid and its conjugate base, or a weak base and its conjugate acid. For example, an acetic acid buffer consists of acetic acid, CH, COOH, and its conjugate base, the acetate ion CH3 COO. Because ions cannot simply be added to a solution, the conjugate base is added in a salt form (eg., sodium acetate NaCH COO). IVO Aze s o o o ? ApH -- 0.363 Submit My Answers Give Up Incorrect, Try Again; 5 attempts remaining Buffers work because the conjugate acid-base pair work together to neutralize the addition of H' or OH ions. Thus, for example, if H ions are added to the acetate buffer described above, they will be largely removed from solution by the reaction of Hwith the conjugate base: Provide Feedback Continue H+ + CH, COO CH, COOH Similarly, any added OH ions will be neutralized by a reaction with the conjugate acid OH + CH3 COOHCHCOO + H2O This buffer system is described by the Henderson-Hasselbalch equation [conjugate base] pH = pK. log [conjugate acid)