Question

2) Ethylenediamine tetraacetic acid (EDTA) is a hexaprotic acid that was used as a food preservative to prevent metal leaching in canned food before monolayer coatings were developed. Let’s say that you find an old can of spam in your grandparents kitchen from 1946, and one of the listed ingredients is EDTA. You decide to collect the fluid from the spam container and titrate it with base to determine the concentration of EDTA.

Write the chemical formula for EDTA with all of the acidic hydrogen atoms listed first

Determine the molarity of a potassium hydroxide solution you make by dissolving 8.557 grams into a 750.00 mL volumetric flask to titrate your sample.

Write the balanced chemical reaction that occurs when you titrate your potassium hydroxide solution into the spam fluid (assume only EDTA is present in the spam).

If it takes 45 mL of your base solution to titrate the spam fluid to the end point, what is the concentration of EDTA in the spam container in molarity?

Answer 1

molarity of a potassium hydroxide (KOH) solution (M) = moles*1000 / volume(mL)

moles = weight/ molar mass; molar mass of KOH = 56

moles = 8.557/56 = 0.1528; volume = 750 mL

M = 0.1528*1000 / 750 = 0.2037 mol/L

molarity of a potassium hydroxide (KOH) solution (M) is 0.2037 M

EDTA - 2,2',2'',2'''-(Ethane-1,2-diyldinitrilo)tetraacetic acid - C₁₀H₁₆N₂O₈ - it is tetra acidic compound.

EDTA reacts with 4 equivalent of base, that is KOH to forma salt.

4 KOH + C10H16N2O8 ---------------->4 K⁺ + (C10H12N2O8)^-4 + 4 H₂O

At the end point, 1 equivalent or one mole of EDTA nueatralized by 4 equivalent or moles of KOH.

45 mL of 0.2037 M KOH solution reacts with EDTA.

moles = M *V /1000 = 0.2037*45 / 1000 = 0.0092 moles

4 mole of KOH nueatralized by 1 mole of EDTA.

0.0092 moles of KOH nueatralized by X mole of EDTA .

0.0092/ 4 = 0.023 moles

molar mass of EDTA - 292.24

weight = moles * molar mass = 0.023*292.24 = 0.67 g

The amount of EDTA is 0.67g

Molarity o EDTA solution- The volume is not given in the question. Let us assume the volume is 1000 mL

(M) = moles*1000 / volume(mL)

M = 0.023 *1000 / 10000 = 0.023 M