Base on the question all about the human eye were an optic nerve of it needs an energy of 2.10x10^-17J that could trigger a series of impulses that eventually reach to the brain. So the possible photons of blue light needed for for this energy is 52 photons
Molar mass RbMnO₄ = 204.40 g/mol
1 mole ---------- 204.40 g
7.88 mole ------ ?
mass = 7.88 * 204.40 / 1
mass = 1610.672 g
hope this helps!
Actual yield of Fe2(So4)3 = 18.5g
2FePo4 + 3Na2SO4 -> Fe2(SO4)3 + 2Na3PO4
Mole of FePO4 = mass of it / its molar mass =
25 g / (55.8 + 31 + 16*4) = 0.166 mol
every 2 mole of FePO4 will form 1 mole of Fe2(SO4)3
Mole of Fe2(SO4)3 produced = 0.166 / 2 = 0.0829 mol
0.0829 * (55.8*2 + 3*(32.1+ 16*4)) = 33.148 g of Fe2(SO4)3
18.5 / 33.148 * 100 = 55.8%
