Question

What percent of glucose, C6H12O6, is carbon?







What percent composition of phosphorus in Zn3(PO4)2? This means to find the percent composition of each element in the compound (Zn, P, and O)









What percent of FeSO4 • 6H2O is Fe?






What percent of AgNO3 is silver?






How many grams of aluminum can be recovered from a 34.5 g sample of Al2O3?







What is the molar mass of P4O10? This just means to add up the masses of all the atoms in the formula. See the example on the front page.





Write the name of Fe2(CO3)3. _____________________________________________
How many grams of iron can be recovered from a 115 g sample of Fe2(CO3)3?






Write the name of SO3. ________________________________________________
In a 63.17 g sample of SO3, how many grams are sulfur?







What is the name of Cu(C2H3O2)2? _____________________________________________________
What is the percent of hydrogen in Cu(C2H3O2)2?

Answer 1

1) What percent of glucose (C6H12O6) is carbon?
- Molar mass = 6(12.01) + 12(1.008) + 6(16.00) = 180.16 g/mol
- Mass of C = 6(12.01) = 72.06 g
- %C = 72.06 / 180.16 × 100 = 40.00%

2) Percent composition of Zn3(PO4)2 (Zn, P, O)
- Molar mass = 3(65.38) + 2[30.97 + 4(16.00)] = 386.08 g/mol
- %Zn = 196.14 / 386.08 × 100 = 50.82%
- %P = 61.94 / 386.08 × 100 = 16.04%
- %O = 128.00 / 386.08 × 100 = 33.16%

3) What percent of FeSO4·6H2O is Fe?
- Molar mass = 55.85 + 32.06 + 4(16.00) + 6(18.016) = 260.01 g/mol
- %Fe = 55.85 / 260.01 × 100 = 21.48%

4) What percent of AgNO3 is silver?
- Molar mass = 107.87 + 14.01 + 3(16.00) = 169.88 g/mol
- %Ag = 107.87 / 169.88 × 100 = 63.53%

5) How many grams of aluminum can be recovered from 34.5 g Al2O3?
- %Al in Al2O3 = 2(26.98) / [2(26.98)+3(16.00)] = 53.96 / 101.96 = 52.93%
- Grams Al = 34.5 × 0.5293 = 18.3 g Al (to 3 sig figs)

6) Molar mass of P4O10
- = 4(30.97) + 10(16.00) = 283.88 g/mol

7) Name of Fe2(CO3)3 and grams of Fe in 115 g sample
- Name: iron(III) carbonate
- Molar mass = 2(55.85) + 3(12.01) + 9(16.00) = 291.73 g/mol
- %Fe = 111.70 / 291.73 = 38.27%
- Grams Fe = 115 × 0.3827 = 43.0 g Fe

8) Name of SO3 and grams of S in 63.17 g SO3
- Name: sulfur trioxide
- %S = 32.06 / (32.06 + 3·16.00) = 32.06 / 80.06 = 40.04%
- Grams S = 63.17 × 0.4004 = 25.3 g S

9) Name of Cu(C2H3O2)2 and percent H
- Name: copper(II) acetate
- Molar mass = 63.55 + 4(12.01) + 6(1.008) + 4(16.00) = 181.64 g/mol
- Mass H = 6(1.008) = 6.048 g
- %H = 6.048 / 181.64 × 100 = 3.33%

If you want these with different atomic weight precision or rounded differently, tell me and I’ll adjust.