I am confused about finding the moles of the titrant and the moles of the unknow

Question

I am confused about finding the moles of the titrant and the moles of the unknown acid in this problem. If somebody could please explain step-by-step how to find the moles of the titrant and the moles of the unknown acid, I would be very appreciative.

ons: Read all test directions carefully. The directions explain exactly what each set of questions requires to answer those questions Read each question carefully and thoroughly. Before answering a question, determine exactly what is being asked. All work must be shown by the student as to how they arrived at the final answer to receive full credit on this assignment. All values are assumed to be measured in the data set and significant figures must be applied accordingly A student wishes to determine the molar mass of an unknown acid. The student begins by diluting a 10.0 mL portion of sodium hydroxide to a final volume of 400 mL using distilled water. The solution was standardized using potassium hydrogen phthalate (KHP) as the analyte and sodium hydroxide as the titrant. The standard solution of sodium hydroxide was found to have a concentration of 0.2086 M. The standard solution was then used to determine the molar mass of a Prompt: monoprotic acid. The data collected is summarized below HA (aq) + NaOH (aq) ? NaA (aq) + H2O (l) Trial I 1.125 0.26 70.65 Trial 2 1.387 0.12 87.55 Trial 3 1.096 0.05 69.04 Student Data Value Sample Mass (g) Initial Volume of Titrant (mL): Final Volume of Titrant (mL) Volume of Titrant (mL) Moles of Titrant (mol) Moles of Unknown Acid (mol) 70:34415 66

Explanation / Answer

moles of titraant = volume of titrant* molarity of titrant ( in this case NaOH)

volume is given in ml, that need to be converted to liters, since molariry is moles/Liters. 1000ml= 1L

trial:1

moles of titrant = 0.2086*70.39/1000=0.015

trital :2 , moles of tirant = 0.2086*87.43/1000=0.018

trial3 : moles of tirant = 0.2086*68.99/1000 = 0.014

from the reaction HA(aq)(monoprotic acid)+ NaOH(aq) ---------->NaA (aq)+ H2O(l)

one mole of NaOH consumes 1 mole of HA for reaction.

hence moles of HA are same as moles of NaOH, the tirant

moles of HA: trial :1= 0.015, trial:2=0.018 and trial-3 = 0.014

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