Answer:
I never did this but i think its d 37.5٪ lmk if i got it right pls and srry if i didnt
I'll go with B, have a good day
A Brønsted-Lowry base is a base is a proton acceptor.
In the only case where this is done is when HCO3- accepts a proton and becomes H2CO3.
In the other cases, HCO3- is donating a proton which makes it an acid.
a) When the reaction takes place a yellow precipitate will be formed.
b) The law of conservation of mass is true.
<u>Explanation:</u>
a) When a lead nitrate solution is mixed with a potassium chromate solution, a yellow precipitate containing lead forms according to the equation:
→ 
b) Law of conservation of mass for the given reaction is true.
From the given table we know the mass of reactants and its products.
Law of conservation of mass is a principle when a reaction takes place in a closed system, the mass of the products and reactants in the system doesn't change.
⇒The sum of the mass of the reactants = The sum of the mass of the products.
The sum of the reactants = 128.71+128.97.
= 257.68 g.
The sum of the products = 154.10+103.58.
= 257.68 g.
Thus law of conservation of mass is true for the above reaction.
8,766 hours is your answer :)