The semiconductor gallium arsenide, GaAs, is used in highspeed integrated circuits, light-emitting diodes, and solar cells. Its density is 5.32 g/cm³. It can be made by reacting trimethylgallium, (CH₃)₃Ga, with arsine gas, AsH₃. The other product of the reaction is methane, CH₄. 

(a) If you reacted 450.0 g of trimethylgallium with 300.0 g of arsine, what mass of GaAs could you make? 

(b) Which reactant, if any, would be left over, and how many moles of the leftover reactant would remain? 

(c) One application of GaAs uses it as a thin film. If you take the mass of GaAs from part (a) and make a 40-nm thin film from it, what area, in cm², would it cover? Recall that 1 nm = 1 x 10^-9 m.