Unisciti a migliaia di studenti che si affidano a noi per superare al meglio i loro esami!
Scelta multipla
What is the pH of the buffer prepared by mixing 200 mL of 0.15 M HNO2 (Ka = 4.0 x 10^-4) and 150 mL of 0.10 M sodium nitrite?
A
3.35
B
2.85
C
3.75
D
4.25
0 Commenti
Guida verificata passo dopo passo
1
Calculate the moles of HNO2 by multiplying its concentration (0.15 M) by its volume (200 mL converted to liters).
Calculate the moles of sodium nitrite (NaNO2) by multiplying its concentration (0.10 M) by its volume (150 mL converted to liters).
Use the Henderson-Hasselbalch equation to find the pH of the buffer: \( \text{pH} = \text{pKa} + \log \left( \frac{[\text{A}^-]}{[\text{HA}]} \right) \), where \( \text{pKa} = -\log(\text{Ka}) \).
Substitute the calculated moles of \( \text{A}^- \) (sodium nitrite) and \( \text{HA} \) (HNO2) into the Henderson-Hasselbalch equation.
Solve the equation to find the pH of the buffer solution.