The balanced chemical reaction is given above however I believe the coefficients are wrong. It should be:
4K + O2 = 2K2O
We use data from that reaction to obtain relationships between substances. We are given the amount of potassium that reacts. We proceed as follows:
1.52 mol K ( 2 mol K2O / 4 mol K ) = 0.76 mol of K2O is formed
Take 23mols and multiply it by the atomic mass of Li:
23mol * 6.94g/mol = 159.62g
Question:
Each liter of air has a mass of 1.80 grams. How many liters of air are contained in 2.5 x103) kg of air?
Answer:
11.48106 L
The given elements put into an equation using their symbols are as follows:
Pb +

=

+ Ag
Since there are 2 Pb on the right side of the equation, you would change the coefficient of Pb on the left side to 2:
2Pb +

=

+ Ag
Since there are 2 Acetate on the right side of the equation, you would change the coefficient of Silver Acetate on the left side to 2:
2Pb +

=

+ Ag
Now there are 2 Silver on the left side, so you change the coefficient of Silver on the right side to 2:
2Pb +

=

+ 2Ag
That is your final equation
The coefficients are 2 + 2 = 1 + 2