Maleic acid is a carbon-hydrogen-oxygen compound used in dyeing and finishing fabrics and as a preservative of oils and fats.
* In a combustion analysis, a 1.054-\rm g sample of maleic acid yields 1.599 \rm g of \rm CO_2 and 0.327 \rm g of \rm H_2O.
* When 0.609 \rm g of maleic acid is dissolved in 25.00 \rm g of glacial acetic acid, the freezing point drops by 0.82 ^\circ \rm C. Maleic acid does not ionize in glacial acetic acid, which has a freezing-point depression constant of K_{\rm f}=3.90~^\circ {\rm C}/m.
* In a titration experiment, a 0.4250-\rm g sample of maleic acid is dissolved in water and requires 34.03 \rm mL of 0.2152 M \rm KOH for its complete neutralization.
* The \rm pH of 0.215 \rm g of maleic acid in 50.00 \rm mL of aqueous solution is found to be 1.80.
Part A
Determine the empirical formula for maleic acid. Enter the atoms in order of \rm C, \rm H, and \rm O.
Part B
Determine the molecular formula for maleic acid. Enter the atoms in order of \rm C, \rm H, and \rm O.
Express your answer as a chemical formula.
Part C
Based on the titration data, how many ionizable \rm H atoms are in each molecule of maleic acid, \rm C_4H_4O_4?
Express your answer as an integer.
I GOT THE PART A and B which is CHO and C_4H_4O_4 respectively, can anyone help me for part C?
part c.
mols C4H4O6 = grams/molar mass = 0.4250/116.07 = 0.00366
mols KOH added = L x M = 0.03403 x 0.2152 = 0.00732. Therefore, the KOH must have titrated 2 H ions (from 0.007323/0.0036615) = 1.99995 = 2.0
Thank you very much.
1.75
中餐厅-金山影视
Sure, I'd be happy to help with part C! To determine the number of ionizable \rm H atoms in each molecule of maleic acid, we can use the information given in the titration experiment.
In the titration, it is given that 0.2152 M \rm KOH is required to completely neutralize a 0.4250 g sample of maleic acid. From this, we can calculate the number of moles of maleic acid:
moles of maleic acid = mass / molar mass = 0.4250 g / (molar mass of maleic acid)
The molar mass of maleic acid can be calculated using the empirical formula (CHO), which has a molar mass of 12.01 g/mol for carbon, 1.01 g/mol for hydrogen, and 16.00 g/mol for oxygen.
So, the molar mass of maleic acid is:
molar mass of maleic acid = (4 * molar mass of carbon) + (4 * molar mass of hydrogen) + (4 * molar mass of oxygen)
Using the values:
molar mass of maleic acid = (4 * 12.01 g/mol) + (4 * 1.01 g/mol) + (4 * 16.00 g/mol)
Now we can calculate the number of moles of maleic acid:
moles of maleic acid = 0.4250 g / (molar mass of maleic acid)
Next, we can use the balanced chemical equation for the neutralization reaction between maleic acid and KOH to determine the stoichiometric ratio between maleic acid and ionizable \rm H atoms.
From the balanced equation, it is clear that 1 mole of maleic acid reacts with 2 moles of KOH, producing 2 moles of water. Therefore, the number of moles of ionizable \rm H atoms in each mole of maleic acid is equal to twice the number of moles of KOH used in the titration.
number of moles of ionizable \rm H atoms = 2 * (0.2152 mol/L * 0.03403 L)
Finally, we can calculate the number of ionizable \rm H atoms in each molecule of maleic acid using Avogadro's number:
number of ionizable \rm H atoms = number of moles of ionizable \rm H atoms * Avogadro's number
So, after performing the calculations, you will get the number of ionizable \rm H atoms in each molecule of maleic acid expressed as an integer.
I hope this helps! Let me know if you have any more questions.
To determine the number of ionizable hydrogen atoms in each molecule of maleic acid (C4H4O4), we need to consider the titration data.
In the titration experiment, 0.2152 M KOH (potassium hydroxide) solution is used to neutralize maleic acid. The volume of KOH required for neutralization is given as 34.03 mL.
From the balanced chemical equation of the neutralization reaction between maleic acid and KOH, we can determine the stoichiometry between the acid and the base. The equation is:
C4H4O4 + 2KOH -> K2C4H2O4 + 2H2O
In this equation, we can see that one molecule of maleic acid reacts with two molecules of potassium hydroxide, producing one molecule of potassium hydrogen maleate (K2C4H2O4) and two molecules of water.
From the balanced equation, it is clear that the number of ionizable hydrogen atoms in maleic acid is equal to the number of potassium hydrogen maleate molecules formed. Since one molecule of maleic acid forms one molecule of potassium hydrogen maleate, the number of ionizable hydrogen atoms is 1.
Therefore, there is 1 ionizable hydrogen atom in each molecule of maleic acid (C4H4O4).