3. A compound contains 40% carbon and 6.67% hydrogen by mass. The rest is oxygen. [5] a) Calculate the empirical formula of the compound. b) If the M, of the compound is 60 , what is its true formula? (A, values: H=1,C=12,O=16 ) 4. Amounts from Reactions When baking soda (NaHCO3) is heated, it releases carbon dioxide gas, which is responsible for the rising of cookies, donuts, and bread. (a) In one reaction, 11g of CO2 was produced. Convert this mass of CO2 to moles of CO2 [2] (b) Convert the moles of CO2 above to atoms of CO2[1] 1. Grams to Atoms A penny weighs 2.15g but contains only 0.14g copper (Cu). How many copper atoms are present in a quarter? 2. Empirical Formulae [4] What are the empirical formulae of compounds with the following compositions: (a) 50.05%S,49.95%O (b) 31.42%S,31.35%O, and 37.23%F