1. How many grams of Mno, are required to obtain 0.028 moles?
2. How many mole are present in 5.7 L of methane
(CH4) gas at STP?
3. How many molecules of lactose, C12,H22, O11,are present in 12 g of substance?
4. How many grams are required for 1.5 x 102° molecules of Cl2 gas?
Please help

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 !

c- cold periods in earth's history during which glaciers covered much of the surface.

explanation:

wher is the rest of the question

pv=nrt

explanation: