Please help Date: In Experiment 625, “Estimating the Acid Content of Fruit Juice
ID: 591983 • Letter: P
Question
Please help
Date: In Experiment 625, “Estimating the Acid Content of Fruit Juices" two samples of orange juice were titrated with sodium hydroxide, NaOH. The molarity of NaOH was determined in a previous experiment and is shown as item (2) below. Obtain and calculate items (4) (11) for both replicates in Part II below to determine the amount of citric acid in orange juice. Follow guidance for calculations, where indicated. For full credit, show calculations and report answers with correct units/significant dizits. (7.5 pts) a. Part 1A, Reading the Buret Use the buret images below to find the volume of NaOH used in both replicates of Experiment 625 The grey color represents the NaOH left in the buret while the white color represents volume of NaOH used in the titrations. Enter the NaOH volumes on line (4) in Part IB below. NOTE: each unlabeled line on the buret represents 0.10 mL and the buret can be read to +/- 0.05 mL z2 Replicate #1 Part IB, Enter values in Data Table (1) Volume of Fruit Juice in flask, mL Replicate #2 b. Replicate #1 Replicate #2 (2) Molarity of NaOH solution, mol/L ,0998I moV/L (3) Initial Buret Reading, mi 0.00 mL 0.00 (4) Final Buret Reading, ml (read from above) mL c. Part II. Calculations Replicate #1 Replicate #2 Step 1: Calculate volume of NaOH required for titration: (5) Volume of NaOH, mL: (4) (3) (6) Moles of NaOH: (2) x (5) x (IL /1000mL) (7) Moles H,C,H507 : (6) x (1 mol / 3 mol) Step 2: Calculate moles of NaOH required: Step 3: Calculate moles of H:CSH,O, titrated in juice: Step 4: Calculate molar mass of H,C&H;,O,: Step 5: Calculate mass of H,CsH,O, in juice: (8) Molar Mass H,C&H;,O, g/mol: (9) Mass HCsH,0,,g: (7) x (8) (10) Mass H,C&HsO-; per mL, gmL: (9)/(1) Step 6: Calculate mass of H,C&HsOper; mL of juice: Step 7: Calculate average mass of H,C&H; 0, per mL of juice for both replicate samples: (11)Average mass of H,CsH,O, per mL, gimlExplanation / Answer
1. Extimation of acid in fruit juice
a. Reading the buret
Relicate #1 : 21.65 ml
Replicate #2 = 21.6 ml
b. Data table
Replicate #1 Replicate #2
(1) volume of fruit juice (ml) 20 20
(2) molarity NaOH(M) 0.0998
(4) NaOH added (ml) 21.65 21.6
c. Calculations
(5) NaOH added (ml) 21.65 21.6
(6) moles NaOH (mol) 0.002161 0.002156
(7) moles H3C6H5O7 0.0007203 0.0007187
(8) molar mass of acid 192.12 g/mol
(9) mass H3C6H5O7 (g) 0.1384 0.1381
(10) mass acid/ml juice(g/ml) 0.00692 0.006905
(11) average acid/ml juice (g/ml) 0.0069125
formulas,
moles = grams/molar mass
moles = molarity (M) x volume (L)
mass = moles x molar mass