Answer:
pH = 3.65
Explanation:
given data
pKa of HNO2 = 3.40
nitrous acid (HNO2) = 0.110 M
NaNO2 = 0.200 M
to find out
What is the pH
solution
we get here ph for acidic buffer that is express as
pH = pKa + log(salt÷acid) ........................1
put here value and we get
pH = 3.40 + log(0.200÷0.110)
pH = 3.65
Answer: The net ionic equation will be as follows.

Explanation:
The chemical equation for the given reaction is as follows.

We know that a strong acid or base will dissociate completely into a solvent whereas a weak acid or base dissociates partially into the solvent. Hence, the ionic equation will be as follows.
Now, we will cancel the spectator ions from the above equation. Therefore, the net ionic equation will be as follows.

or,
Answer:
D 2,2
Explanation:
We can see that there are 2 chlorines on the reactant side so there has to be a 2 on the product side
Now we have Na + Cl2 --> 2NaCl
The problem now is that there are 2 sodiums on the product side so add a 2 to the Na on the reactant side
2Na + Cl2 --> 2NaCl
Now it's balanced!
States that the properties of elements are periodic or recurring and are correlated to their atomic number.