Question

Slow Help T ED.21* 9.4. ADS 115 a aa a ab ap & 2. 15 11.16 LIVE! !! 3. When determining the empirical formula experimentally, you will not know the number of moles directly since we do not have instrumentation that can measure the quantity of moles. Instead the mass can be used. In an experiment it is found that an aluminum oxide sample contains 1.35 g of aluminum and 1.20 g of oxygen. a. How many moles of aluminum and oxygen are present in the sample described above? Express your answer as a "pseudo" chemical formula placing the calculated molar quantities as subscripts b. The formula you wrote above in "a" may look odd since the subscripts are not whole numbers. Therefore, you will need to divide each value by the smallest number of moles that you have calculated. Then express your answer as chemical formula placing the values you just calculated as subscripts Are the values found above whole numbers? If not, then you will need to multiply all subscripts by the same smallest whole number to get to all subscripts as whole number values. Show all of your work and then express your answers as the chemical formula for aluminum oxide. Yours answers should match the formula given above for aluminum oxide. If not be sure to have your instructor check your work 4. In the experiment that follows, you will use what you have learned above to experimentally determine the empirical formula for composition of an unknown metal obtained from a carelessly labeled bottle that reads "13x19 mole samples of a Group 1 and 2 Metals." Read Task View fault Style - English (USA) WWNur

Answer 1

Aluminium oxide Al = 1.359 , Oxygen = |.209 molee of Al = gram weight of Al - 1.35g = 0.05 mol molar mass Catomic mars 26.90 Ilmul moler of O = = gram weight of oxygey = 1.209 = 0.075 Atomic mass af o 16/mal mol Chemical formula = (Alios 0.075 - .05 = 1 os ratio of Al as whole No. = 1 ratio of o " " " = 0.075 = 15 Now chenaical formala - Al, Ois To find whole number ratio should meeltiplied by 2 . Then chemical farmula Al 1x2 Orsxz = Al₂O3 final chemical formula = |A203)