In CaCO3 + HCI — CaCl2 + H2O +CO2, how many liters of carbon
dioxide gas, measured at STP, can be obtained from 45.0 g of calcium
carbonate? (Gas Stoichiometry)

(no3)⁻n has oxidation number x,o has oxidation number -2.(x*1 -2*3) charge of the nitrate ion, and we know that charge of the nitrate ion =-1.so,(x*1 -2*3) =-1x-6=-1x=+5answer a. +5.

Answer two atoms of oxygen;