Tooth enamel is largely hydroxyapatite
The reverse process, called remineralization, is the body's natural defense against tooth decay. Acids produced from food remove the OH- ions and thereby weaken the enamel layer. Most toothpastes contain a fluoride compound such as
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Chemistry
- Sodium tripolyphosphate (Na5P3O10) is used in many synthetic detergents. Its major effect is to soften the water by complexing Mg2+ and Ca2+ ions. It also increases the efficiency of surfactants, or wetting agents that lower a liquids surface tension. The K value for the formation of MgP3O103 is 4.0 108 The reaction isMg2+(aq)+P3O105(aq)MgP3O103(aq). Calculate the concentration of Mg2+ in a solution that was originally 50. ppm Mg2+ (50. mg/L of solution) after 40. g Na5P3O10 is added to 1.0 L of the solution.arrow_forwardThe preparation of cis-platin [Pt(NH 3) 2CI 2], an anticancer drug, uses an equilibrium reaction: K 2PECI 4(aq) + 2NH 3(aq) = 2 KCI(aq) + Pt(NH 3) 2CI 2(aq). Which of the following conditions would lead to an increase in the amount of Pt(NH 3) 2CI 2 formed? The use of a low concentration of NH3 The addition of a large concentration of KCI The use of a large concentration of NH3 The use of a stoichiometric ration of K2PTCI4 and NH3arrow_forwardTo determine the amount of magnetite, Fe3O4, in an impure ore, a 1.5419-g sample is dissolved in concentrated HCl, giving a mixture of Fe2+ and Fe3+. After adding HNO3 to oxidize Fe2+ to Fe3+ and diluting with water, Fe3+ is precipitated as Fe(OH)3 by adding NH3. Filtering, rinsing, and igniting the precipitate provides 0.8525 g of pure Fe2O3. Calculate the %w/w Fe3O4 in the sample. Hint: The analyte is Fe.arrow_forward
- To determine the amount of magnetite, Fe3O4, in an impure ore, a 1.5419 g sample is dissolved in concentrated HCl, giving a mixture of Fe2+and Fe3+. After adding HNO3 to oxidize Fe2+ to Fe3+and diluting with water, Fe3+is precipitated as Fe(OH)3 by adding NH3. Filtering, rinsing, and igniting the precipitate provides 0.8525 g of pure Fe2O3. Calculate the %w/w Fe3O4 in the sample.arrow_forward31) Which of the following compounds precipitates from a solution that has the concentrations indicated? (See Appendix J for Ksp values.) (a) CaCO3: [Ca2+] = 0.003 M, [CO32−][CO32−] = 0.003 M (b) Co(OH)2: [Co2+] = 0.01 M, [OH–] = 1 ×× 10–7 M (c) CaHPO4: [Ca2+] = 0.01 M, [HPO42−][HPO42−] = 2 ×× 10–6 M (d) Pb3(PO4)2: [Pb2+] = 0.01 M, [PO43−][PO43−]= 1 ×× 10–13 Marrow_forwardA weighed sample of sodium nitrite was treated with 0.05 mol of ceric sulfate in solution, in air-free conditions. The resulting solution was titrated with standard Fe(II) solution and 0.01 mol of Fe(II) were required. Determine the moles of sodium nitrite present in the weighed sample. NO2– + 2 Ce4+ + H2O → NO3– + 2 Ce3+ + 2 H+ Fe2+ + Ce4+→ Fe3+ + Ce3+arrow_forward
- Calculate the solubility of Co(OH)3 (s), Ksp = 2.5 x 10-43, in a solution at pH= 4.0arrow_forward2 Consider the insoluble compound aluminum phosphate, AIPO4. The aluminum ion also forms a complex with hydroxide ions. Write a balanced net ionic equation to show why the solubility of AIPO4 (s) increases in the presence of hydroxide ions and calculate the equilibrium constant for this reaction. For Al(OH)4, K₁= 7.7x1033. Be sure to specify states such as (aq) or (s). K= Submit Answer 54 $ R % 5 Use the References to access important values if needed for this question. T ? Retry Entire Group 9 more group attempts remaining Cengage Learning | Cengage Technical Support A 6 MacBook Pro Y H & 1 U - A * 8 1 A ( 9 ) 0 0 P K L Previous Email Instructor { [ + 11 = Next Save and Ex }arrow_forwardConsider the insoluble compound cobalt(II) hydroxide , Co(OH)2 . The cobalt(II) ion also forms a complex with ammonia . Write a balanced net ionic equation to show why the solubility of Co(OH)2 (s) increases in the presence of ammonia and calculate the equilibrium constant for this reaction.For Co(NH3)62+ , Kf = 7.7×104 . Be sure to specify states such as (aq) or (s). + + K =arrow_forward
- A solution containing copper(II) nitrate (aq) first has some aqueous ammonia added to it. A white precipitate forms. Addition of more aqueous ammonia results in the precipitate dissolving, forming a clear dark blue solution. Write reactions for each step in the process. Hints: Ksp Cu(OH)2 = 2.2 X 10-20; Kb NH3 = 1.8 X 10-5 and Kf Cu(NH3)42+ = 1.1 X 1013arrow_forwardConsider the insoluble compound cobalt(II) hydroxide , Co(OH)2 . The cobalt(II) ion also forms a complex with ammonia . Write a balanced net ionic equation to show why the solubility of Co(OH)2 (s) increases in the presence of ammonia and calculate the equilibrium constant for this reaction.For Co(NH3)62+ , Kf = 7.7×104 . Be sure to specify states such as (aq) or (s). Net Equation= ______ K= ______arrow_forwardIn Questions 1 through 6, you will be calculating the initial concentrations of Fe³+ ([Fe³+10) and SCN ([SCN]o) for each of the reactions you will perform. You should transfer the answers to these questions to the appropriate ICE table(s) on the "Data and Calculations" sheet. In all five reactions, you will be using 5.0 mL of 0.0020 M Fe(NO3)3. Each reaction mixture will be diluted to a final volume of 10.0 mL. What is [Fe³+]o in all five of the reactions you will study? Type your answer, WITHOUT UNITS, in the box below. Include 2 significant figures. If you want to enter your answers in scientific notation, use the format that Blackboard recognizes: 1.5 x 10-3 would be entered as 1.5E-3 (no spaces). QUESTION 2 In Test Tube 1, you will be using 1.0 mL of 0.0020 M KSCN. Each reaction mixture will be diluted to a final volume of 10.0 mL. What is [SCN ] in Test Tube 1? Type your answer, WITHOUT UNITS, in the box below. Include 2 significant figures. QUESTION 3 In Test Tube 2, you will be…arrow_forward
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