Which equation demonstrates the law of conservation of mass? A. C + 02- C20
B. H2SO4 + Zn – 4ZnSO + H2
c. Mg + S - MgS2
D.2H2 + O2 – 2H20
Please help ASAP !

The number of moles of a given mass of a substance can be found without knowing its molecular formula or molar mass. true false

How many moles of bromine are needed to produce 3.23 moles of potassium bromide

Which statement correctly describes the phosphate ion, ? it is composed of one phosphorus atom and four oxygen atoms covalently bonded together, and there is a –3 charge distributed over the entire ion. it is composed of one phosphorus atom and four oxygen atoms covalently bonded together, and there is a –3 charge on the phosphorus atom. it is composed of one phosphorus atom and four oxygen atoms ionically bonded together, and there is a –3 charge distributed over the entire ion. it is composed of one phosphorus atom and four oxygen atoms ionically bonded together, and there is a –3 charge on the phosphorus atom.