![]() ![]() Keywords: calcium hidroxide, ph evaluation, dioxide carbon.Ĭonservative and radical endodontic treatments use calcium hydroxide as a therapeutic support due to its action as a bactericide and inducer of mineralized tissue. However, the high alkaline pH of the calcium hydroxide powder was preserved in the absence of CO 2, maintaining its reparative and antimicrobial properties. The results demonstrated that in the presence of CO 2, calcium hydroxide showed a marked loss of and in relation to the decrease in pH. The indices of pOH, and were obtained by mathematical calculations after determining the pH. 0.12g of calcium hydroxide powder was used for each of 16 aliquots diluted in 100 mL of deionized water and distributed in 2 samples of 8 aliquots. This work involved an evaluation of calcium hydroxide powder in the absence and presence of CO 2. Simões, BR 104, Km 97, Tabuleiro dos Martins 57072-970 Maceió - AL, Brazil IIILaboratório de Dentística e Endodontia, Faculdade de Odontologia da Universidade Federal Alagoas FOUFAL, Centro de Ciências da Saúde (CSAU),Campus A. Simões, BR 104, km 97, Tabuleiro dos Martins 57072-970 Maceió - AL, Brazil IILaboratório de Química Analítica, Universidade Federal de Alagoas, Centro de Ciências Exatas e Naturais (CCEN), Campus A. ILaboratório de química de produtos naturais LPqRN, Universidade Federal de Alagoas, Instituto de Química e Biotecnologia (IQB), Cidade Universitária, Br 101, Km 14 Norte, Tabuleiro dos Martins 57072-970 Maceió - AL, Brazil ![]() What is the pH of the solution?Īnswer: M=n/L : M acetic acid= 0.00026/2.5 = 1.Comparative evaluation of the pH of calcium hydroxide powder in contact with carbon dioxide (CO 2)Īmaro de Mendonça Cavalcante I,III, * Jose Carlos de Souza Lima II Lucineide de Melo Santos III Paulo César Costa de Oliveira II Karlos Antonio Lisboa Ribeiro Júnior I Antonio Euzébio Goulart Sant'ana I A more trickier one: 0.00026 moles of acetic acid are added to 2.5 L of water. Seem too low to be true? Think again, if the pH is >7, the solution will be basic, hence the hydronium ions will be low compared to the hydroxide (OH - ions).ĥ. Now let's do the inverse: Say you have a solution with a pH of 9.4. PH= -log= 1.48 : The solution is highly acidic!Ĥ. What is the corresponding pH of this solution, and based on your answer identify whether the solution is acidic, basic or neutral.Īnswer: Using the formula \(pH \approx -log\) Let's say the concentration of Hydronium ions in an aqueous solution is 0.033 mol/L. Which one should you add?Īnswer: Since the goal is to lower the pH to its ideal value, we must add acidic solution to the pool.ģ. Those specific chemicals are included in the set, so no need to worry about which one you have to use and (eek!) if they are legal for public use). Shockingly, you realize it's set at 8.3! Horrified, you panic and are unsure whether you should add some basic or acidic chemicals in your pool (being mindful of the dose, of course. The instruction manual advises to keep it between 7.2-7.6. You decide to test the pH of your brand new swimming pool on your own. Which one should she buy?Īnswer: The brand that has a pH of 6.8 since it's under 7 (neutral) but very close to it, making it slightly acidic.Ģ. The first has a pH of 3.6, the second of 13, the third of 8.2, the fourth of 6.8 and the fifth of 9.7. She finds 5 brands that she really likes, but since she never took any introductory chemistry classes, she is unsure about which one to purchase. A hair stylist walks into a store and wants to buy a shampoo with slightly acidic/neutral pH for her hair. An increase in the \(HIn\) acid concentration causes the equilibrium to shift to the right (towards products), whereas an increase of the \(In^-\) base concentration causes the equilibrium to shift to the left (towards reactants).ġ. ![]() Thus, as the concentration of \(H_3O^+\) (H +) increases or decreases, the equilibrium shifts to the left or right accordingly. It is important here to note that the equation expressed in figure 4 is in equilibrium, meaning Le Chatelier's principle applies to it. \(In^-\) is the conjugate base of the pH indicator. ![]()
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