What is the molar mass of 0.500 g of unknown monoprotic acid used in titration, if 22.5 mL of 0.15 M NaOH solution was required to neutralize it?
I do not need the answer, but instead an example of how to do a question just like it.
moles base = .0225*.15
moles acid= mass/molmass
molmass= mass/moles acid= .5/(.0225*.15)
To determine the molar mass of the unknown monoprotic acid, you can follow these steps:
Step 1: Write the balanced equation for the neutralization reaction between the acid and the base. In this case, assuming the acid is monoprotic and reacts with NaOH (a strong base), the equation can be written as follows:
Unknown acid (HA) + NaOH -> NaA + H2O
Step 2: Calculate the number of moles of NaOH used in the neutralization reaction. This can be done using the formula:
moles of NaOH = (volume of NaOH used in liters) x (molarity of NaOH in moles per liter)
In this example, the volume of NaOH used is 22.5 mL, which is equal to 0.0225 L. The molarity of NaOH is given as 0.15 M. Therefore:
moles of NaOH = 0.0225 L x 0.15 moles/L
Step 3: Determine the stoichiometric ratio between NaOH and the unknown acid. From the balanced equation, we can see that the ratio is 1:1. This means that 1 mole of NaOH reacts with 1 mole of the unknown acid.
Step 4: Calculate the number of moles of the unknown acid used in the neutralization reaction. Since the stoichiometric ratio between NaOH and the unknown acid is 1:1, the moles of NaOH used will also be equal to the moles of the unknown acid used.
moles of HA = moles of NaOH
Step 5: Convert the mass of the unknown acid (given as 0.500 g) to moles using its molar mass. Divide the mass of the unknown acid by its molar mass:
moles of HA = mass of HA / molar mass of HA
Step 6: Set up an equation using the two expressions for the number of moles of the unknown acid:
moles of HA (from step 4) = moles of HA (from step 5)
Step 7: Rearrange the equation to solve for the molar mass of the unknown acid:
molar mass of HA = mass of HA / moles of HA
By following these steps and plugging in the appropriate values from the problem, you should be able to find the molar mass of the unknown monoprotic acid used in the titration.