7. Nick and Lesley add 25 cm of hydrochloric acid to 1 g of calcium carbonate. They also add 25 cm of ethanoic acid to 1 g of calcium carbonate.
Both acids have the same concentration.
Carbon dioxide is made in both reactions.
i. Both acids make the same volume of carbon dioxide.
Explain why.
[1]

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 !

plants need sunlight, water, and carbon dioxide to make food. plants use the raw materials of water, nutrients they absorb from soil, and carbon dioxide to make sugars the plant can use. energy from the sun and chlorophyll are also needed.