Answer to Question #112464 in General Chemistry for jovanni

Question

The semiconductor gallium arsenide (GaAs) is in high speed integrated circuits, light-emitting diodes, and solar cells. Its density is 5.32 g/cm3. It can be made by reacting trimethyl gallium (CH3)3Ga with arsine, AsH3, gas. The other product is methane, CH4. Write a balanced chemical reaction. If 300.0 g of trimethyl gallium is reacted with 200.0 g of arsine, what mass of gallium arsenide could be produced? What is the limiting reactant?

Answer 1

Solution.

(CH₃)₃Ga + AsH₃ $\to$ GaAs + 3CH₄;

1 mol 1 mol 1 mol

m((CH₃)₃Ga) = 300g;

m(AsH₃) = 200g;

$\nu$((CH₃)₃Ga) = (300g$\sdot$ 1mol )/114.83g =3.92 mol;

$\nu$ (AsH₃) = (200g $\sdot$ 1 mol)/77.95 g = 3.85 mol;

We use the given quantity of AsH₃ ( the limiting reactant) to calculate the quantity of GaAs formed.

m(GaAs) = (3.85mol(AsH₃)$\sdot$ 144.64g)/1 mol (AsH₃) = 556.86 g;

The limiting reagent in a chemical reaction is the substance that is totally consumed when the chemical reaction is completed. The limiting reagent in this reaction is AsH_3.

Answer: m(GaAs) = 556.86 g;

The limiting reagent in a chemical reaction is the substance that is totally consumed when the chemical reaction is completed. The limiting reagent in this reaction is AsH₃.