1. A sample contains an unknown amount of tartaric acid, H2C4H4O6. If 0.3888 g of the sample requires 37.74 mL of 0.1000 M NaOH to neutralize the H2C4H4O6 completely, what is the percentage of H2C4H4O6 in the sample? The molar mass of H2C4H4O6 is 150.09 g/mol. The balanced equation for the reaction is:
H2C4H4O6 + 2 NaOH → 2 H2O + Na2C4H4O6
2. Sodium thiosulfate, Na2S2O3, is an important reagent for titrations. Its solutions can be standardized by titrating the iodine released when a weighed amount of potassium hydrogen iodate, KH(IO3)2 (389.912 g/mol), is allowed to react with excess potassium iodide in acidic solutions. The net ionic equations are:
production of iodine from KH(IO3)2 : IO3- +5I- +6H+ →3I2 +3H20
titration of iodine: I2 +2S2O3^2- →2I– +S4O6^2–
What is the molarity of a sodium thiosulfate solution if 32.96 mL are required to titrate the iodine released from 0.1278 g of KH(IO3)2?
1. A sample contains an unknown amount of tartaric acid, H2C4H4O6. If 0.3888 g of the...
A saturated solution of calcium iodate contains 2.37 g/L of Ca(IO3)2. (a) What is the solubility of calcium iodate in mol/L? (b) What are the concentrations of Ca2+ and IO3 – ion, respectively, in the saturated solution? (c) Calculate the Ksp value for Ca(IO3)2. Part b ) Silver ion, Ag+ , readily forms complex ion, Ag(S2O3)2 3– , with thiosulfate, S2O3 2– , according to the following equation: Ag+ (aq) + 2S2O3 2– (aq) ⇌ Ag(S2O3)2 3– (aq); Kf =...
6. Calcium oxide reacts with nitric acid to produce calcium nitrate and water. How many grams of calcium oxide are required for complete reaction with 30.0 mL of 0.587 M nitric acid? The molar mass of calcium oxide is 56.077 g/mol. (Hint: start by writing the balanced equation for the reaction.) 7. A sample contains an unknown amount of succinic acid, H2CHO. If 0.3540 g of the sample requires 42.70 mL of 0.1000 M NaOH to neutralize the H2C,H404 completely,...
A 0.5g sample of cement is added to a flask and is placed in a hot water bath with ~20ml of ethylene glycol where it was mixed with a stir bar for 20 minutes. After 20 minute, the liquid was put through a vacuum filtration to collect the liquid. The filtrate was then transferred to another flask. To the filtrate, 3.00ml of 0.1M HCl was added. 50ml of 0.005M potassium iodate, and 0.5g of solid potassium iodide was also added...
Calculate the molarities and normalities of the following solutions. The reactions are those given in problem 1. 4.50 g of Hg(NO3)2 in 150.0 mL of solution 15.0 g of Ba(OH)2 in 1.15 L of solution 12.0 g of KCN in 200 mL of solution A solution of sodium thiosulfate, Na2S2O3 is standardized using pure potassium dichromate, K2Cr2O7, as the primary standard. A sample of K2Cr2O7 weighing 0.2263 g was dissolved, acidified, and excess KI added to liberate I2. The I2...
A solution of tartaric acid is prepared of concentration 1.2174 g L -1 and it is found that 50.0 ml of the solution requires 21.48 mL of 3.78 × 10-2 mol L -1 sodium hydroxide for complete neutralization. The formula of tartaric acid is C4H6O6 and its relative molecular mass is 150.2. Calculate how many of the hydrogens in a molecule of tartaric acid are ionised in aqueous solution.
A solution of tartaric acid is prepared of concentration 1.2174 g L -1 and it is found that 50.0 ml of the solution requires 21.48 mL of 3.78 × 10-2 mol L -1 sodium hydroxide for complete neutralization. The formula of tartaric acid is C4H6O6 and its relative molecular mass is 150.2. Calculate how many of the hydrogens in a molecule of tartaric acid are ionised in aqueous solution.
2. A 0.1000 g sample of KBrO3 was dissolved in dilute acid and treated with an excess of KI. BrO3 +91 +6H+ → Brº+ 313 + 3H20 The generated 13. required 11.92 mL of a Na2S2O3 solution to reduce it to 1. Use the above balanced equation and those found in the introduction to determine the molarity of the Na2S2O3 solution. 3. The following data was obtained for an iodometric titration of an ascorbic acid tablet. Mass of tablet: 1.2191...
buffer solutions
1. Determine the volume of 1.0 M tartaric acid, H2CaH&Os, solution that when diluted to a total volume of 250.0 mL produces a solution that is 0.050 M in tartaric acid. 2. Determine the mass of potassium hydrogen tartrate, KHC&H4O6, required to prepare 250.0 mL of a solution that is 0.050 M in hydrogen tartrate ion. 3a. Write a balanced equation and corresponding K, expression for the ionization of the weak acid lactic acid (HC3HsO3, Ka 1.62 x...
Is the calculated concentration for IO3-
in the data table correct, and if not, how do I calculate it. Also,
the questions below the data table in the second picture. How are
they calculated?
2. The molar solubility of Cal(IO3)2 in pure water Temperature of the saturated solution of calcium iodate: Volume (or mass) of saturated calcium iodate solution titrated:O -24 °C ted:1 Q mL (or g) Data Trial 1 Trial 2 Trial 3 Volume of Na2S203 titrant Final buret...
13:17 51439 87% < t go TOⓇ cao , 2NW 220 Question 7 (22 marks) 2 Naz S-03 +Iman Naz Sobota I 03, + I fexcess +H it (5 marks) 5.8emmo Hulle (a) A certain mass of iodine (12) reacted completely with 48.0 mL of 2.25 M sodium thiosulfate' solution. Calculate the mass of jodine used for the reaction. (5 marks) (b) A student performed an experiment to determine the concentration of an unknown sodium thiosulfate solution. First, 5.88 mmol...