mass of carbonic acid = 300g
molar mass of H2CO3 = 2H + C + 3 O
= 2 x 1.008+ 12.01 + 3 x 16
= 62.03g/mol
moles of H2CO3 = mass/Molar mass
= 300/62.03
= 4.8364 moles
1 mole H2CO3 has 3 moles Oxygen
4.8364 moles H2CO3 contains
= 3 x 4.8364 moles Oxygen = 14.509 moles Oxygen
moles = mass/Molar mass
mass of oxygen = moles x Molar mass of Oxygen
= 14.509 x 16
= 232.15g Oxygen
mass of oxygen in 300g of carbonic acid(H2CO3) = 232.15g
I don’t really know but hope you figure it out
Explanation:
According to the law of conservation of mass, mass can neither be created nor it can be destroyed. But it can be simply transformed from one form to another.
Therefore, when 
is added to NaCl then the compound formed will have same mass as that of reactants.
Total mass of reactants is (169.87 + 58.44) g/mol = 228.31 g/mol
Total mass of products is (143.32 + 84.99) g/mol = 228.31 g/mol
Thus, we can conclude that mass of the new mixture will stay the same.
This problem is very easy to answer. You simply have to look at the subscripts of each element of the compound.
1. For caffeine, which has a molecular formula of C₈H₁₀N₄O₂, it contains 8 atoms of Carbon, 10 atoms of Hydrogen, 4 atoms of Nitrogen and 2 atoms of Oxygen.
2. For Iron(III) Sulfate, which has a molecular formula of Fe₂(SO₄)₃, it contains 2 atoms of Iron, 3 atoms of Sulfur, and 12 atoms of Oxygen.
