i need help with a packet that im struggling with my questions are

Question

write the total number of atoms present for the following questions:
a. 4SO2 now i tried and got 8O'S and 1S
b. 8O2 i tried and got 16 all together
c. 3Al2(SO4)3 i tried and got 6Al, 3S, and 12O
my next question is one way to test salinity of a water sample is to add a few drops of silver nitrate solution with a known concentration. as the solutions of sodium chloride and silver nitrate mix, a precipitate of silver chloride forms, and sodium nitrate is left in solution. translate these sentences into a balanced chemical equation.
now i don't understand it but i tried some of it i just don't know where to put it at in the sentence but i know in the question i would need NaCl, Ag (NO3) and i know i need plus signs and a yield sign but i just don't know where everything goes or how to set it up can u help me
now i have to balance an equation and from that answer i have to translate it into a chemical equation my question is NaHCO3(S)=Na2CO3(S)+H2O(g)+CO2(g) now i tried the problem and got 2NaHCO3(S)=Na2CO3(s)+CO2(g)+H2O(g) and after that i have to translate it into a chemical equation but i don't know if my answer is correct to translate it