Question
Can someone solve this lab for me, please
32 B. Molecular mass of an unknown acid. 1. Unknown number 2. Molarity of sodium hydroxide solution Titrations ast Pacit flask 1 flask 2 flask 3 3. Mass of fask + unk. 1.2 IA 4. Mass of flask 5. Mass of unknown 6. Final buret reading 8. Initial buret reading 9. Volume of NaOH soln. ig 5514 10. Moles of unknown acid (assume monoprotic) Molecular mass of acid Average molecular mass Cool 11. etal ic, a 12. oks of acid ick are tua see nts olc 13. Deviation of each mol, mass from average Average deviation of molecular mass Suggest experimental modifications you could make if the acid to be titrated has low 14. 15. solubility in water. Some of the Learning Objectives of this experiment are listed on the first page of this experiment. Did you achieve the Learning Objectives? Explain your answer 16. aeeesalbte website, in whole or to put o 201s cengag9 Learning. All Rights Resurved. May not be soanned, copled or duptleared, or posted to a pubilety accesible
Explanation / Answer
Volume of NaOH used = Intital buret - final buret
Volume of NaOH used = V1 = 17 18.6 16.8 ml
= 0.017 0.0186 0.0168 L
No. of moles of NaOHused = V1 * Molarity of NaOH = V1 * 0.1 mol/L
No. of moles of NaOHused = 0.0017 0.00186 0.00168 moles
No. of moles of acid = no. of moles of NaOH used
No. of moles of acid = 0.0017 0.00186 0.00168 moles
GIven mass of unkonwn acid = 0.5 0.5 0.5 g
Molar mass of acid = mass / No. of moles of acid
Molar mass of acid = 294.12 268.82 297.62 g/mol
Average molecular mass of acid = 286.85 g/mol
Deviation = 7.27 - 18.03 10.77
Average deviation = 12.02