A1.00 l solution contains 15.52 g of nitrous acid, hno2. what mass of sodium nitrite, nano2, should be added to it to make a buffer with a ph of 3.56? ka (hno2) = 4.0 × 10–4.

Hello!

First, we need to calculate the moles of HNO₂ which are:



The pKa for HNO₂ is pKa= -log(Ka)= -log(4,0 * 10⁻⁴)=3,39

Now, we can use the Henderson-Hasselbach equation to determine the moles of NaNO₂. Since both compounds (Weak base and acid) have the same volume, we can use moles instead of concentrations:



Finally, we go from moles of NaNO₂ to grams of NaNO₂ using the molar mass



So, the required amount of NaNO₂ is 33,8077 g

Have a nice day!

Yes she is correct. the answer is completely correct