A 500.0-mL buffer solution is 0.100 M in HNO2 and 0.150 M in KNO2. Determine whether or not
each of the following additions would exceed the capacity of the buffer to neutralize it.
a. 250 mg NaOH
b. 350 mg KOH
c. 1.25 g HBr
d. 1.35 g HI
Can you explain to me how to go about this question?
No to all the above
None of these exceed the capacity. If you're doing this on mastering chem, these specific measurements are all "no"
no
To determine whether each addition would exceed the capacity of the buffer to neutralize it, we need to compare the concentrations of the added substances with the concentrations of the buffer components (HNO2 and KNO2). Here's how you can approach each part of the question:
a. 250 mg NaOH:
To determine if the buffer can neutralize this addition, we need to convert the mass of NaOH to molarity. First, calculate the moles of NaOH using its molar mass:
Molar mass of NaOH = 22.99 g/mol + 16.00 g/mol + 1.01 g/mol = 39.00 g/mol
Moles of NaOH = 250 mg / 39.00 g/mol = 6.41 x 10^-3 mol
Since NaOH completely dissociates in water, the concentration of NaOH in the solution after the addition is the same as the moles of NaOH. So, the concentration of NaOH is 6.41 x 10^-3 M.
Compare the concentration of NaOH (6.41 x 10^-3 M) with that of the HNO2 (0.100 M) component of the buffer. Since the concentration of NaOH is much lower than the concentration of HNO2, the buffer can neutralize the NaOH addition.
b. 350 mg KOH:
Follow the same process as above to find the concentration of KOH in the solution after the addition. Remember to use the molar mass of KOH (39.10 g/mol) to calculate moles and then divide by the total volume of the solution (500 mL or 0.500 L).
Compare the concentration of KOH with the concentration of the KNO2 (0.150 M) component of the buffer to determine if the buffer can neutralize the KOH addition.
c. 1.25 g HBr:
Convert the mass of HBr to moles using its molar mass (molar mass of HBr = 1.01 g/mol + 79.90 g/mol = 80.91 g/mol). Then, divide by the total volume of the solution (0.500 L) to find the concentration of HBr.
Compare the concentration of HBr with the concentration of the HNO2 (0.100 M) component of the buffer to determine if the buffer can neutralize the HBr addition.
d. 1.35 g HI:
Convert the mass of HI to moles using its molar mass (molar mass of HI = 1.01 g/mol + 126.90 g/mol = 127.91 g/mol). Then, divide by the total volume of the solution (0.500 L) to find the concentration of HI.
Compare the concentration of HI with the concentration of the HNO2 (0.100 M) component of the buffer to determine if the buffer can neutralize the HI addition.
By comparing the concentrations of the additions with the concentrations of the buffer components, you can determine whether or not the buffer can neutralize each addition.