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Question

rome File Edit View History Bookmarks People Window Help 100% Sur ALEKS-Anastasia Menkhaus An Analytical Chemist weighs × x c Secure Ihtps:/www.swh.aleks.comaleksogjnis.exe/to u-IgNskr78P3H-LITX1858270VADBLZ2tZ.TTdkWze YABeatAgŽejDICExuPSnwuR2-CYsBlg SIMPLE REACTIONS Standardizing a base solution by titration An A chemistry student needs to standardize a fresh solution of sodium hydroxide. He carefully weighs out 113. mg of oxalic acid (H,C,0a), a diprotic acid that can be purchased inexpensively in high purity, and dissolves it in 250. mL of distilled water. The student then titrates the oxalic acid solution with his sodium hydroxide solution. When the titration reaches the equivalence point, the student finds he has used 58.7 mL of sodium hydraxide solution. Calculate the molarity of the student's sodium hydroxide solution. Be sure your answer has the correct number of significant digits Check Explanation

Explanation / Answer

H2C2O4 + 2NaOH ----- Na2C2O4 +H2O

Molar mass of oxalic acid (H2C2O4) = 2 * 1 + 2 * 12 + 4 * 16 = 90 gm/mol

Number of moles of oxalic acid = Mass/molar mass = 113/90 * 10^(-3) = 1.25555 * 10^(-3) moles

Number of moles of NaOH required = 2 * Number of moles of oxalic acid = 2 * 1.255555 * 10^(-3) moles

=> 0.00251111 moles

Volume of NaOH(in L) * Molarity of NaOH = 0.00251111

58.7/1000 * Molarity of NaOH = 0.00251111

Molarity of NaOH = 0.042778M