Question

How many mL of the titrant Sr(OH)2 is needed to titrate 3.09 mL of 0.75 M HCIO4, if the molarity of the titrant is 0.03? If 12.73 mL of the analyte HCIO4 is titrated with 9.63 mL of 0.500 M Sr(OH)2 determine the molarity of the analyte solution. Select the correct answer to the questions below with regards to the KHC204/K2C204 buffer. What characteristic of this buffer will improve its buffer capacity? Choose.. What component of the buffer will NaOH react with when added to the buffer mixture? Choose... A What component of the buffer will HCl react with when added to the buffer mixture? Choose... Which of the following pH values are within the buffer range for a buffer containing 0.5 M HNO2 and 0.5 M NaNO2? The Ka for NO2 is 4.5x10-5. Select one or more: 2.16 3.81 5.09 7.11 0.57

Answer 1

$V_{Sr(OH)2}=\frac{M_{HClO4} \times V_{HClO4}}{M_{Sr(OH)2}} \times \frac{2 \ mol \ Sr(OH)_2}{1 \ mol \ HClO_4}$

$V_{Sr(OH)2}=\frac{0.75 \ M \times 3.09 \ mL}{ 0.03 \ M} \times \frac{2 \ mol \ Sr(OH)_2}{1 \ mol \ HClO_4}$

$V_{Sr(OH)2}=154.5 \ mL \simeq 155 \ mL$

$M_{HClO4}=\frac{M_{Sr(OH)2} \times V_{Sr(OH)2} }{V_{HClO4}} \times \frac{1 \ mol \ HClO_4}{2 \ mol \ Sr(OH)_2}$

$M_{HClO4}=\frac{0.500 \ M \times 9.63 \ mL }{12.73 \ mL } \times \frac{1 \ mol \ HClO_4}{2 \ mol \ Sr(OH)_2}$

$M_{HClO4}=0.189 \ M$