please someone solve this for me. please show work so i can do similar problems.
ID: 1036849 • Letter: P
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please someone solve this for me. please show work so i can do similar problems. help please! The problem is to solve for region 3
cid-Base Titrations, Problem Set actic Acid Problems: 1 Consider the titration of 10.0 mL of 0 250 M lactic acid with 0 0991 M NaOH. Calculate the pH at region 3, and the pH when the volume of the titration equals, 0.00 mL, 7.50 mL, ' equivalence volume, 14.5 mL, and 35.0 ml 2, Explain in your own words why phenolphthalein is an appropriate indicator to use for the titration of lactic acid in yogurt with NaOH. Using the internet to do some research, find two other indicators that you think would be appropriate to use for the determination of lactic acid in yogurt. List the criteria you used to choose the appropriate indicatorExplanation / Answer
The base of titration is the neutralization reaction between an acid and a base. 10 ml of 0.250 M of lactic acid will neutralized by 0.0991 M of NaOH.
M1V1 = M2 V2
V2 = M1V2 / M2
= (0.250 x 10 ) / 0.0991 = 25 ml of NaOH needed.
At the end point, or after adding 25 ml of NaOH, pH will be 7 or neutral. That means, as the NaOH adding to lactic acid solution acidic pH will come down , up to 7.
if added NaOH < 25 ml , pH will be <7
greater amount of base or NaOH (like 35 ml) addition will lead to basic pH or >7
Lactic acid is weak organic acid and sodium hydroxide is a strong base, so when we are titrating them together, the pH of titration will in basic range or 8-11 range. So a indicator which is lies in that range must be used to get the exact end point or titre value. The pH range of phenolphthalein is between 8.3-10. so it can detect the neutralization by colour change.
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