color(blue)("Step 1: Assume 100 g sample to find mass of each element")Step 1: Assume 100 g sample to find mass of each element
"C" = 34.6" g"C=34.6 g
"H" = 3.85" g"H=3.85 g
"O" = 61.55" g"O=61.55 g
color(blue)("Step 2: Find number of moles from the mass of each element.")Step 2: Find number of moles from the mass of each element. Use the periodic table to find molar masses of each element
"C" = (34.6 cancel"g")/1 *(1" mol")/(12 cancel"g") = 2.88" mol"
"H" = (3.85 cancel"g")/1 *(1" mol")/(1.00 cancel"g") = 3.85" mol"
"O" = (61.55 cancel"g")/1 *(1" mol")/(16 cancel"g") = 3.85" mol"
color(blue)("Step 3: Divide all the mole numbers by the smallest mole value of them all")
"C" = (2.88cancel"mol")/(2.88 cancel"mol") = 1
"H" = (3.85cancel"mol")/(2.88 cancel"mol") = 1.33
"O" = (3.85 cancel"mol")/(2.88 cancel"mol") = 1.33
color(blue)("Step 4: Multiply the number by a factor which will give out a whole number ratio.")
"C" = 1 * (3) = 3
"H" = 1.33 * (3) = 3.99~~4
"O" = 1.33 * (3) = 3.99~~4
color(blue)("Step 5: Combine elements and attach their corresponding mole ratios. Then, find the empirical formula mass")
C_(3)H_(4)O_(4)->(104" g")/"mol" = "empirical formula mass"
color(blue)("Step 6: Divide given molecular formula mass by the empirical formula mass to get a factor.")
This factor will tell you how many times to multiply the subscripts to get your mole ratios for the molecular formula
("Molecular formula mass")/("Empirical formula mass") ->[(208 cancel"g")/(cancel"mol")]/[(104 cancel"g")/(cancel"mol")]= 2
C_(3)H_(4)O_(4) -> color(orange)(C_(6)H_(8)O_(8) = "Molecular Formula")
"Answer": C_(6)H_(8)O_(8)
