I'll do A for you. They are all double displacement reactions. So recall: AB+CD--> CB+AD . Also, knowing the charges will help and make this so easy.
Based on the compounds given, I can say that the substance that is considered essential in the plastic making is NITRIC ACID. This substance is also known as aqua fortis and spirit of niter wherein this decomposes into oxides of nitrogen and water. The answer would be the last option. Hope this helps.
Its A because the number if every element on one side is equal to the number of elements on the other?
First determine the molality of the solution. m = (w solute)/[(mm solute)(kg solvent)] -- mm means molar mass. So,
m = (14.7 g)/[(180 g/mol)(0.150 kg) =0.544 mol/kg = 0.544 m
Change in boiling point (∆t) = m x Kbp = (0.544 m)(0.512 °C/m) = 0.28°C
The solution will boil at 100.28°C at 1 atm.
the density if water is 1.00 g/ml and Kb= 0.512 C/m