How do i do this question??
A 10.00ml Sample was taken from a 2Liter Container of Tropicana Orange juice. This sample was analyzed for its citric acid content by titration with a known 0.1112M NaOH base solution. A Phenoolphthalein indicator was added to detect the endpoint for the titration. a pink endpoint colour was observed after 23.75ml of the NaOH soultion was added to the Orange juice solution.
1) Calculate the # moles of NaOH used to reach the end point
is 1ml of NaOH equal to 1 gram???
is 0.593796 the right answer??
2) Calculate the # moles of citric Acid at the endpoint
Where do i start to solve this???
THANKYOU
To solve this question, we can break it down into two parts:
1) Calculate the number of moles of NaOH used to reach the endpoint:
To start, we need to calculate the volume of NaOH used. In this case, it is given that 23.75 mL of the NaOH solution was added to the orange juice. Now, we can convert this volume to moles.
To do this, we'll use the equation:
moles of NaOH = volume of NaOH (in liters) x molarity of NaOH
First, we need to convert the volume of NaOH from milliliters to liters:
23.75 mL = 23.75 mL * (1 L / 1000 mL) = 0.02375 L
Now, we can calculate the number of moles of NaOH:
moles of NaOH = 0.02375 L * 0.1112 mol/L = 0.002645 mol
Therefore, the number of moles of NaOH used to reach the endpoint is 0.002645 mol.
So, the answer to this question is not 0.593796.
2) Calculate the number of moles of citric acid at the endpoint:
To determine the number of moles of citric acid, we need to use the balanced chemical equation for the reaction between NaOH and citric acid.
The balanced equation is:
3 NaOH + H3C6H5O7 (citric acid) -> Na3C6H5O7 (sodium citrate) + 3 H2O
From the equation, we can see that 3 moles of NaOH react with 1 mole of citric acid.
Since we found that the number of moles of NaOH used is 0.002645 mol, we can determine the number of moles of citric acid:
moles of citric acid = 0.002645 mol * (1 mol citric acid / 3 mol NaOH) = 0.000882 mol
Therefore, the number of moles of citric acid at the endpoint is 0.000882 mol.
So, the correct answer to this question is not 0.593796.
1) To calculate the number of moles of NaOH used to reach the endpoint, you need to use the volume and concentration of the NaOH solution used.
First, convert the volume of NaOH solution used to liters:
23.75 ml = 23.75/1000 L = 0.02375 L
Next, calculate the number of moles of NaOH:
moles = volume (L) x concentration (M)
moles = 0.02375 L x 0.1112 M = 0.002643 moles
So, the number of moles of NaOH used to reach the endpoint is 0.002643 moles.
Regarding your question: No, 1 ml of NaOH is not equal to 1 gram. The conversion factor between volume and mass depends on the density of the substance, so you cannot assume a direct conversion without additional information.
2) To calculate the number of moles of citric acid at the endpoint, you need to use the balanced equation for the reaction between citric acid and NaOH.
The balanced equation is:
3 NaOH + H3C6H5O7 → Na3C6H5O7 + 3 H2O
From the equation, you can see that 3 moles of NaOH react with 1 mole of citric acid (H3C6H5O7).
Since you have calculated the number of moles of NaOH (0.002643 moles), you can use the ratio from the balanced equation to determine the number of moles of citric acid:
moles of citric acid = 1/3 x moles of NaOH
moles of citric acid = 1/3 x 0.002643 moles
moles of citric acid = 0.000881 moles
So, the number of moles of citric acid at the endpoint is 0.000881 moles.
I hope that helps! Let me know if you have any further questions.