Concept explainers
Interpretation:
The lactic acid (
Concept introduction:
pKa: It is introduced as an index to express the acidity of weak acids, where
In aqueous solution an acid undergoes ionization. The ionization of an acid is can be expressed in terms of equilibrium constant. The quantitative measurement tells about the strength of the acid. Higher the value of
The dissociation constant for the acid is
For simplifications
The lower value of
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Chemistry & Chemical Reactivity
- COHSOH(ag) + H2On + CeHsO (aq) + H3O*(a9) Ka= 1.12 x 10-10 (a) Phenol is a weak acid that partially dissociates in water according to the equation above. Write the equilibrium-constant expression for the dissociation of the acid in water. (b) What is the pH of a 0.75 M CaHsOH(ag) solution? (C) For a certain reaction involving CaHsOH(ag) to proceed at a significant rate, the phenol must be primarily in its deprotonated form, C3H5O (eg). In order to ensure that the CsHsOH(aq) is deprotonated, the reaction must be conducted in a buffered solution. On the number scale below, circle each pH for which more than 50 percent of the phenol molecules are in the deprotonated form (CoHsO (aq). Justify your answer. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 Justification: (d) CeHsOH(ag) reacts with NaOH(ag). Write a net ionic equation representing this reaction (aka: invasion equation). (e) What is the pH of the resulting solution when 30 mL of 0.40 M CSH5OH(aq) is added to 25 mL of 0.60 M NAOH. Show all work…arrow_forwardWhat is the conjugate base of boric acid, B(OH)3? (A) OH– (B) B(OH)4– (C) B(O)(OH)22– (D) B(H2O)(OH)2+arrow_forward27. What is the pH of a neutral solution at 37°C, where Kw equals 2.5 x 10-14 (a) 7.00 (b) 6.80 (с) 13.60 (d) 7.20arrow_forward
- The ionization constant of lactic acid, CH,CH(OH)CO,H, an acid found in the blood after strenuous exercise, is 1.36 x 10-4. What is the concentration of hydronium ion in the solution of 0.102 M lactic acid? CH;CH(OH)CO,H (aq) + H,O (1) → H;O• (aq) + CH;CH(OH)CO, (aq) O 0.00372 M O 0.0165 M O 0.00549 M O 0.227 Marrow_forward8. (a) HA(aq) is a weak acid with a dissociation constant, Ka, of 8.8 x 10−12. What is the pH of a 0.022 M solution of A−(aq)? The temperature is 25 ◦C. (b) For the reaction A(g) =A(l), the equilibrium constant is 0.666 at 25.0 ◦C and 0.222 at 75.0 ◦C. Making the approximation that the entropy and enthalpy changes of this reaction do not change with temperature, at what temperature will the equilibrium constant be equal to 0.777?arrow_forwardThe pH scale for acidity is defined by pH – log10 H*| where |H*| is the concentration of hydrogen ions measured in moles per liter (M). (A) The pH of Drano is 13.3. Calculate the concentration of hydrogen ions in moles per liter (M). [H*] = M (B) The pH of rain water is 5.5. Calculate the concentration of hydrogen ions in moles per liter (M). [H*] = Marrow_forward
- The active ingredient of bleach such as Clorox is sodium hypochlorite (NaClO). Its conjugate acid, hypochlorous acid (HClO), has a Ka of 3.0 × 10^–8. (a) The undiluted bleach contains roughly 1 M NaClO. Calculate the pH of 1 M NaClO solution. (b) Some applications require extremely diluted bleach solution, such as swimming pools. Suppose the solution in (a) is diluted by 10,000 -fold. Calculate the pH of the diluted solution, and demonstrate that you can still neglect the autoionization of water in your calculation. (c) Suppose the solution in (a) is diluted by 1 million-fold, briefly explain how your approach will be different. Write the equation with [H3O+] as the unknown, but you do not need to solve it.arrow_forward(b) What will happen if acetic acid (HC2H3O2) is added to water? O An equilibrium will form between its molecular form, HC2H3O2, and the species formed by removal of water, C2H2O. O An equilibrium will form between its molecular form, HC2H3O2, and the species formed by addition of water, H3C2H3O3. O Acetic acid is a strong acid and will ionize completely. O An equilibrium will form between its molecular form, HC2H3O2, and the ionized form, H* and C2H3O2. O Acetic acid is a weak acid and will not ionize completely. Hint Attempts: 1 of 15 used Submit Save for Later TIng I aI system, SOme of UIS energy Can De transieIICU To une su t ST國 ост 15 MacBook Airarrow_forward2. Which of the following solutions has a pH = 15? (A) A solution cannot have a pH = 15. (B) 1.0 x 10-15 M NaOH (C) 10.0 M NaOH (D) 15 M NaOH (E) 1.0 M NaOHarrow_forward
- At 50 °C, the ion-product constant for H2O has the valueKw = 5.48 x 10-14. (a) What is the pH of pure water at50 °C? (b) Based on the change in Kw with temperature,predict whether ΔH is positive, negative, or zero for theautoionization reaction of water:2 H2O(l) ⇌ H3O+(aq) + OH-(aq)arrow_forwardThe pH reading of a sample of each substance is given. Calculate the hydrogen ion concentration of the substance. (Give your answers in scientific notation, correct to one decimal place.) (a) Vinegar: pH = 3 %3D [H+] = x 10 M (b) Crackers: pH = 7.2 %3D [H+] = x 10 M (p ツarrow_forwardWrite the formula of the conjugate base of CH3CO2Harrow_forward