Answer:
pH = 3.73
Step-by-step explanation:
Let's apply the Hendersson Hasselbah equation
pH = pKa + log [salt / acid]
HNO₂ → pKa = 3.16
Concentration of salt and acid must be M
Let's determine molarity of salt
5.80 g . 1 mol /68.99 g = 0.0840 moles of sodium nitrite
0.0840 mol / 0.150L of solution = 0.56 M
pH = 3.16 + log (0.56/0.15)
pH = 3.73