Answer:
a. 167 mL.
b. 39.3 %.
Explanation:
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In this case, for the undergoing chemical reaction, since 45.0 g of aluminum react, based on the 2:3 mole ratio with sulfuric acid, we can compute the required moles as shown below:
[tex]n_{H_2SO_4}=45.0gAl*\frac{1molAl}{27.0gAl} *\frac{3molH_2SO_4}{2molAl} =2.50molH_2SO_4[/tex]
Next, since the molarity of a solution is computed based on the moles and volume (M=n/V), we can compute the required volume of sulfuric acid as shown below:
[tex]V=\frac{n}{M}=\frac{2.50mol}{15.0mol/L}=0.167L[/tex]
That in mL is 167 mL.
Moreover, for the percent yield, we compute the grams of aluminum sulfate that are produced based on the required 2.50 moles of sulfuric acid:
[tex]m_{Al_2(SO_4)_3}=2.50molH_2SO_4*\frac{1molAl_2(SO_4)_3}{3molH_2SO_4}*\frac{342.15gAl_2(SO_4)_3}{1molAl_2(SO_4)_3} \\\\m_{Al_2(SO_4)_3}=285.13gAl_2(SO_4)_3[/tex]
Therefore the percent yield is:
[tex]Y=\frac{112g}{285.13g}*100\%\\\\Y=39.3\%[/tex]
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