What volume (to the nearest 0.1 mL) of 7.10-M HCl must be added to 0.550 L...

What volume (to the nearest 0.1 mL) of 7.10-M HCl must be added to 0.550 L of 0.350-M K2HPO4 to prepare a pH = 7.50 buffer?

Expert Solution

We are working with a Strong Acid/Weak Base solution. The reaction is extensive so we will use up all of the HCl. The reaction table is as follows:

                 HCl      +     HPO₄^2-    ---->       Cl^-    +    H₂PO₄^-
initial:       7.10x          0.1925                     0               0
delta:      -7.10x          -7.10x                   7.10x         7.10x
equil:          0         0.1925 - 7.10x           7.10x         7.10x

Note: 0.1925 = 0.350 x 0.550

Remember the equation: pH = pK_a + log(n_b/n_a)
The p_Ka for HPO₄^2- = 7.21
So we get: 7.5 = 7.21 + log([HPO₄^2-]/[H₂PO₄^-])
7.5 = 7.21 + log((0.1925 - 7.10x)/(7.10x))
Solve for x and this will be the amount of HCl in L to prepare a pH = 7.60 buffer. Don't forget to convert to mL.

x = 9.19 10^-3 L = 9.19 mL

queen_honey_blossom answered 2 years ago

1a)What volume (to the nearest 0.1 mL) of 7.10-M HCl must be added to 0.550 L...

1a)What volume (to the nearest 0.1 mL) of 7.10-M HCl must be added to 0.550 L of 0.350-M K2HPO4 to prepare a pH = 7.50 buffer? b)What volume (to the nearest 0.1 mL) of 7.60-M NaOH must be added to 0.700 L of 0.200-M HNO2 to prepare a pH = 3.20 buffer? c)How many mL (to the nearest mL) of 0.250-M KF solution should be added to 740. mL of 0.220-M HF to prepare a pH = 3.10 solution? b)What...

a) What volume (to the nearest 0.1 mL) of 6.60-M HCl must be added to 0.450...

a) What volume (to the nearest 0.1 mL) of 6.60-M HCl must be added to 0.450 L of 0.200-M K2HPO4 to prepare a pH = 7.40 buffer? b) What volume (to the nearest 0.1 mL) of 7.10-M NaOH must be added to 0.600 L of 0.250-M HNO2 to prepare a pH = 3.10 buffer?

What volume (to the nearest 0.1 mL) of 5.30-M NaOH must be added to 0.700 L...

What volume (to the nearest 0.1 mL) of 5.30-M NaOH must be added to 0.700 L of 0.350-M HNO2 to prepare a pH = 3.70 buffer? What volume (to the nearest 0.1 mL) of 4.80-M HCl must be added to 0.550 L of 0.250-M K2HPO4 to prepare a pH = 8.00 buffer?

What volume (to the nearest 0.1 mL) of 6.00-M NaOH must be added to 0.400 L...

What volume (to the nearest 0.1 mL) of 6.00-M NaOH must be added to 0.400 L of 0.250-M HNO2 to prepare a pH = 4.30 buffer? What volume (to the nearest 0.1 mL) of 5.50-M HCl must be added to 0.250 L of 0.200-M K2HPO4 to prepare a pH = 7.10 buffer?

What volume (to the nearest 0.1 mL) of 5.20-M NaOH must be added to 0.500 L...

What volume (to the nearest 0.1 mL) of 5.20-M NaOH must be added to 0.500 L of 0.350-M HNO2 to prepare a pH = 3.50 buffer?

a.) What volume (to the nearest 0.1 mL) of 4.50-M NaOH must be added to 0.300...

a.) What volume (to the nearest 0.1 mL) of 4.50-M NaOH must be added to 0.300 L of 0.150-M HNO2 to prepare a pH = 3.20 buffer? ______ mL b.) What volume (to the nearest 0.1 mL) of 4.00-M HCl must be added to 0.700 L of 0.350-M K2HPO4 to prepare a pH = 7.50 buffer? _______ mL

Determine the volume (in mL) of 1.00mol/L HCl that must be added to 750mL of 0.50mol/L...

Determine the volume (in mL) of 1.00mol/L HCl that must be added to 750mL of 0.50mol/L HPO42- to produce a buffer with a pH of 7.00.

Determine the volume (in mL) of 0.411 M hydrochloric acid (HCl) that must be added to...

Determine the volume (in mL) of 0.411 M hydrochloric acid (HCl) that must be added to 448 mL of 0.914 M sodium butanoate (NaC3H7COO) to yield a pH of 5.48. Assume the 5% approximation is valid and report your answer to 3 significant figures. A table of pKa values can be found here. pKa=4.82

Calculate the expected pH when 0.5 mL of 0.1 M HCL is added to 30.0 mL...

Calculate the expected pH when 0.5 mL of 0.1 M HCL is added to 30.0 mL pure water. Do the same calculation when the same amount of HCl is added to 30.0 mL of your original .05M buffer. Compare the calculated pH to the actual measured pH. My buffer has a pH of 5.09 and I used acetic acid which has a pKa of 4.76 2. If you have 50 mL of .05M potassium phosphate buffer pH 7.0 and you...

calculate the change in pH when 3.00 ml of 0.1 M HCL is added to 100...

calculate the change in pH when 3.00 ml of 0.1 M HCL is added to 100 ml of a buffer solution that is 0.1 M in NH3 and 0.1 M in NH4Cl. Calculate the change in pH when 3.00 ml of 0.1 M NaOH is added to the original buffer solution.

Question