Given that 14t = 2d, 5p = 2c, 4c = 9m, and 12p = 63t, what is 15d in the units of m? m. Do NOT enter unit. Assume all the numbers in equalities as exact numbers.

Aphysical change is one that you can put in and remove like a ham sandwich. the stuff you put in there can be changem its not permanet. a chemical change is on that can't be change thats permanet. like when you make a cake and bake it. you can't get those ingredients back.

It would be true sodium reacts with water in a violent way 

Molarity is moles of solute over liters of solution. idk if that is what you are talking about, but you can convert moles of solute to grams of solute using dimensional analyzes by using molar mass found on the periodic table.