Answer:
0.0067 mol/dm³
Step-by-step explanation:
The [H3O+] of HNO2 can be found by using the formula
![[H_3O^( + ) ] = √(Kac)](https://img.qammunity.org/2021/formulas/chemistry/college/8uzkeusg2ihmydd1awlgnshc9o02lnvr2s.png)
Ka is the acid dissociation constant
c is the concentration of the acid
From the question we have
![[H3O^( + ) ] = \sqrt{4.46 * {10}^( - 4) * 0.1} \\ = 0.006678...](https://img.qammunity.org/2021/formulas/chemistry/college/107q16isisg4v9b63rr7uovleb5hozmrby.png)
We have the final answer as
0.0067 mol/dm³
Hope this helps you