Question

A student ran a trial of the experiment. The mass of the emtpy evaporating dish was 4.5000 g. After the reaction, the mass of the evaporating dish with the product, CuO, was 6.4271. How many moles of CuO are in the dish after the reaction?

Answer 1

sowton/ The mass of the empty evaporating dish was 4. 5000 g. The mass of the evaporating dish with the product, wo was 6.42719. in mass of ao present in the dish after the reaction, = (6.4271 - 4.5000) g. = 1.9271 g. Element Symbol Atomic Mass #of Atoms copper Cu 63.546 Oxygen 0 15.9994 The compound whic has lau atom and 1 oxygen atom is known as Copper (11) oxide cu o Molecular weight of CO = Atomic weight of eut Atomic weight oto = (63.546 + 15.9994)gimol = 79.54 54 g/mol Hence molar mass of co= 79.5454 g/mol. converting grams co to moles 19271 g of eu o = 1.92718 - 1.9271 moles 79,54548/moles 7915954 = 0.0242 moles Hence 0.0242 moles of ao presents in the dish after the reaction.