When a mineral was heated in a bunsen flame to constant mass, a colourless gas that turned lime water milky was evolved. the remaining solid was cooled and then added to aqueous hydrochloric acid. vigorous effervescence was seen.

what was the mineral?

a aragonite, caco3

b artinite, mgco3.mg(oh)2.3h2o

c barytocalcite, baco3.caco3

d dolomite, caco3.mgco3

2fe + 3h2so4 -> fe2(so4)3 + 3h2

it is necessary to balance equations in order to get the proper amount of reactants as well as products in order not to make a miscalculation.

you cannot change the subscripts as that would change the substance itself. for instance, diatomic elements such as h2 only have the subscript two when a gas. another example would be so4, if you were to change the subscript, the element would no longer be sulfate.

we change the coefficients instead as that only changes the number of molecules rather than the substance itself.

hope this !

< > according to newton's third law of motion, forces always act in equal but opposite pairs. another way of saying this is for every action, there is an equal but opposite reaction.< >