26. classify each chemical equation as a combination/synthesis , decomposition, single replacement, double replacement, or combustion. a. pb(s) + hg2so4(s)  pbso4(s) +2 hg(l) b. nacl(aq) + agno3(aq)  agcl(s) + nano3(aq) c. 2 h20(l)2 h2(g) + 02(g) 27. find the molar mass of nitric acid (hno3). 28. avogadro’s number refers to a. the maximum number of electrons that all of an atom’s energy levels can accommodate b. the number of protons and neutrons that can fit in the shells of an atom’s nucleus c. the number of particles in one mole of a substance d. the number of particles in exactly 1.0 g of a substance 29. how many moles of oxygen atoms are in 1.5 moles of co2? (sc2c) a. 1 mol b. 1.5 mol c. 2 mol d. 3 mol 30. what is the mass of 0.28 mol of iron ?