A solution of Ca(OH)2 (FM = 74.09) was used in determining the equivalent weight of an unknown acid. To do so, the said solution was standardized against 0.1235 g KHP (FM = 204.22), requiring 7.45 mL to reach the phenolphthalein endpoint. On the other hand, a 0.0543 g unknown acid requires 12.85 ml standard Ca(OH)2 to reach the desired endpoint. a. Calculate the standard normality of Ca(OH)2. b. Calculate the equivalent weight of the unknown acid. c. From the table below, what is the most probable identity of the unknown acid. Probable identity Ascorbic Acid, C6H§O6 Malonic Acid, C3H4O4 Succinic Acid, CH,O4 Citric Acid, CsH3O7 Formula weight Proticity 176.124 104.062 2 118.088 192.124 3

A solution of Ca(OH)2 (FM = 74.09) was used in determining the equivalent weight of an unknown acid. To do so, the said solution was standardized against 0.1235 g KHP (FM = 204.22), requiring 7.45 mL to reach the phenolphthalein endpoint. On the other hand, a 0.0543 g unknown acid requires 12.85 ml standard Ca(OH)2 to reach the desired endpoint. a. Calculate the standard normality of Ca(OH)2. b. Calculate the equivalent weight of the unknown acid. c. From the table below, what is the most probable identity of the unknown acid. Probable identity Ascorbic Acid, C6H§O6 Malonic Acid, C3H4O4 Succinic Acid, CH,O4 Citric Acid, CsH3O7 Formula weight Proticity 176.124 104.062 2 118.088 192.124 3

Fundamentals Of Analytical Chemistry

9th Edition

ISBN:9781285640686

Author:Skoog

Publisher:Skoog

Chapter13: Titrations In Analytical Chemistry

Section: Chapter Questions

Problem 13.5QAP

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Similar questions

A solution of Ca(OH)2 (FM = 74.09) was used in determining the equivalent weight of an unknown acid. To do so, the said solution was standardized against 0.1235 g KHP (FM = 204.22), requiring 7.45 mL to reach the phenolphthalein endpoint. On the other hand, a 0.0543 g unknown acid requires 12.85 mL standard Ca(OH)2 to reach the desired endpoint.a. Calculate the standard normality of Ca(OH)2.b. Calculate the equivalent weight of the unknown acid.c. From the information in the table, what is the most probable identity of the unknown acid?
A chemist receive different mixtures for analysis with the statement that it contain NaOH, NaHCO3 , Na2CO3 or compatible mixtures of these substances together with the inert material. From the data given, identify the respective materials and calculate the percentage of each component. 1.000g samples and 0.2500 N HCl were used in all cases. Sample 1 With phenolphthalein as the indicator, 24.32 ml of HCl was used. A duplicate sample required 48.64 ml HCl using methyl orange as the indicator. Sample 2. With phenolphthalein as the indicator it uses 28.2 ml of HCl to make it colorless and added with methyl orange indicator and uses 11.3 ml of HCl to reach the end point.
3.A sample is known to contain NaOH, Na2CO3 NaHCO3 or compatible mixture of these together with inert matter. With methyl orange, a 1.100 g sample requires 31.40 mL of HCl ( 1.00 mL is equivalent to 0.0140g CaO). With phenolphthalein indicator, the same weight of sample requires 13.30mL of the acid. What is the percent composition of the sample? ww ww
A 22.41 mL of NaOH solution is required to reach the phenolphthalein endpoint in the standardization with 0.276 g of solid, monoprotic primary standard acid (MW 128.33) in a 25.00 mL solution. 12.34 mLof the same NaOH solution was added to titrate 5 mL of vinegar solution to the endpoint. Calculate the mass of acetic acid in this vinegar solution (d = 1.005 g/mL).
Approximately 6 mL of conc. perchloric acid ( 72% ) was transferred to a bottle and diluted with about 1 liter of water. A sample containing 251.5 mg of primary standard Na2B4O7.10H2O (Fwt= 382g/mol) required 27.41 mL of the HClO4 solution to reach the methyl red end point. What is the molar concentration of the HClO4 solution? Na2B4O7.10H2O + HClO4 ------------> NaClO4 H2B4O7.10H2O
A NazCO3 standard solution is prepared by transferring 2.4817 grams of primary standard-grade sodium carbonate to a 250.0 mL volumetric flask, dissolving the sample in -100 ml of distilled deionized water, and diluted to the mark. A 25.00 mL aliquot is taken and titrated with 42.65 mL of HCI solution to the bromocresol green endpoint. Calculate the concentration of the HCI solution. (A 0.1598 M B 0.1098 M c) 0.3196 M (D) 0.05490 M
A mixture contains Na2CO3, NaOH and inert matter. A sample weighing 1.500 g requires 28.85 ml of 0.500N HCI to reach a phenolphthalein endpoint, and an additional 23.85 to reach a methyl orange endpoint.What are the percentages of Na2C03 and NaOH?
A student performed a titration to determine the exact concentration of NaOH(aq). The titration was performed against a standard 0.1000 M HCl(aq) solution. Phenolphthalein indicator was used. The following end-point volumes were recorded by the student in units mL: Trial Number Volume 1 25.06 2 25.15 3 25.02 4 25.17 5 25.07 Calculate the 95% confidence limit. Assume that there is no outlier. Provide your answer to the correct number of decimal places, without units, and without the ± sign. Use the T-table shown below.
(A) if both sentences are true,(B) if both sentences are false,(C) if the first sentence is true but the second is false, and(D) if the first sentence is false but the second is true. 1. In the Winkler Titration Method, sodium thiosulfate is standardized against a known concentration of magnesium iodate. The normality (N) of a solution is always equal to its molarity (M). 2. In the experiment on determining the dissolved oxygen concentration of a water sample, the compound used to acidify the sample was hydrochloric acid. An acidic solution will have a pH greater than 7. 3. Radioactive wastes, like uranium, must be handled and disposed of according to special regulations designed to protect people and the environment. Nuclear power plants produce too much greenhouse gases due to the burning of uranium.
A solution was prepared by dissolving 367 mg of K3Fe(CN)6 (329.2 g/mol) in sufficient water to give 750.0 mL. Calculate (a) the molar analytical concentration and Normality of K3Fe(CN)6. (b) the molar concentration of K+. (c) the molar concentration of Fe(CN)63-. (d) the weight/volume percentage of K3Fe(CN)6.
КНР (ад) + NаОН (ад)- - NAKHP (aq) + H20 (1) Trial V; (mL) V; (mL) 33.87 45.73 2 A student masses out 1.019 grams of KHP, which is dissolved in 25.00 mL of DI water. This KHP solution is titrated with NAOH, as shown in the equation above. Calculate the molarity of the NaOH solution. RE FS F6 F7 FB F10
The hardness of water (hardness count) is usually expressed in parts per million (by mass) of CaCO3. What is the molar concentration of Ca2+ ions in a water sample with a hardness count of 175mg CaCO3il? How many milliliters of concentrated sulfuric acid, 94.0% (w/w), specific gravity of 1.831 are required to prepare 1 liter of a 0.100 M solution? The solubility-product constant for Ce(IO3)3 is 3.2x1010. What is the Ce3+ concentration in a solution prepared by mixing 50.0 ml of 0.0250 M Ce3.. with 50.00 ml of water?