A 20 mL aliquot of skimmed milk was placed in an Erlenmeyer flask. To the flask was added 3 to 4 drops of phenolphthalein. The sample was titrated in triplicate using a previously standardized NaOH solution of 0.101 N concentration. The volumes of NaOH spent in the three experiments to reach chemical equivalence were: Volumes #1 = 3.50 mL #2 = 3.60 mL # 3 = 3.43 mL A control sample of 1.6 g/L of lactic acid was also analyzed in triplicate, the spent volumes of NaOH were: Volumes #1 = 3.41 mL #2 = 3.42 mL # 3 = 3.43 mL Find the acidity of the milk expressed in g/L of lactic acid. Write the neutralization reaction that occurs in the titration process.

What is the molarity of C₁2H22O11 in an aqueous solution that is prepared by dissolving a 29.87 g sample of impure C12H22011 in water to make 725.0 mL of solution. Assume that the sample is 83.0% C12H22011 by mass. Enter your answer in mol L-1, accurate to three significant figures. Do not include units as part of your answer. Use the following molar masses, in g mol-¹, for your calculations. H, 1.008 Number C, 12.01 0, 16.00

A science teacher needs to determine the concentration of an old, unmarked bottle of hydrochloric acid. She prepares a base titrant by dissolving 40.0 g of potassium hydroxide in 500.0 mL of water. The base is pipetted into a 28.00 mL sample of the acid, which also contains phenolphthalein as an indicator. The solution turns from clear to pink after the addition of 7.34 mL of base. What is the concentration of the hydrochloric acid?

A student begins a titration experiment by filling her first buret with unknown acid to the 1.12 mL level.  She fills her second buret with base, NaOH, and records an initial volume of 0.08 mL.  At the end of the titration experiment and after the pale pink endpoint is obtained, she records her final volume of acid in the buret as 18.85 mL, and the final volume of base in the second buret as 28.74 mL.  In the first blank below, please indicate the volume of acid used in her experiment.  In the second blank, please indicate the volume of base used.  For both answers, please report your answer WITH the correct number of significant figures or decimal places, and WITHOUT a unit.    Question 1 options: ___________ answer #1   ___________answer #2

Refer to the solubility curve below to answer this question. How many grams of NH4Cl will dissolve in 1500 g of water at 90 °C? Grams of solute per 100 g H₂O 150 140 130 120 110 100 90 80 70 60 50 40 30 20 10 K Blank 1: NH37 8 NaNO3 KCIO3. KNO3 NHẠC KCI Naci -Ce₂(SO4)3 0 0 10 20 30 40 50 60 70 80 90 100 Temperature (°C)

A biochemist carefully measures the molarity of calcium carbonate in 62. mL of photobacterium cell growth medium to be 67. µM. Unfortunately, a careless graduate student forgets to cover the container of growth medium and a substantial amount of the solvent evaporates. The volume of the cell growth medium falls to 6.0 mL. Calculate the new molarity of calcium carbonate in the photobacterium cell growth medium. Be sure your answer has the correct number of significant digits.

5. If a 7.0 mL sample of vinegar was titrated to the stoichiometric equivalence point with 7.5 mL of 1.5M NaOH, what is the mass percent of CH₂COOH in the vinegar sample? Show your work. Moles of NaOH used= 1.5M x 7.5 mL = 11.25 millimole Moles of acetic acid in vinegar 11.25 millimole Concentration of acetic acid = 11.25 millimole/7.0 mL = 1.61 M Mass % of acetic acid = 1.61 M x 60 g/mol (molar mass of acetic acid) = 96.43% ????? I

On their third titration trial, the CHM 111 student used 18.80 mL of 0.205 M NaOH(aq) to neutralize 25.0 mL of HCl(aq). Calculate the molar concentration of the HCl solution to the correct number of significant figures.

A TUMS tablet was dissolved in 110.00 mL of 0.1022 M HCl and analyzed for CaCO3 according to the procedure described in the lab manual. It took 7.48 mL of 0.1005 M NaOH to reach the endpoint. Calculate the mass of CaCO3 in the TUMS tablet to the correct number of significant figures.

You add 12.5mL of a 5.00M stock solution of sodium hydroxide to a 500mL volumetric flask and dilute to the mark with distilled water. What is the concentration of the resulting solution?