Homework answers / question archive / Rio Salado Community College - CHM MISC Essay Question 1)Phosphoric acid (H3PO4) is used in detergents, fertilizers, toothpastes and flavoring in carbonated beverages

Rio Salado Community College - CHM MISC Essay Question 1)Phosphoric acid (H3PO4) is used in detergents, fertilizers, toothpastes and flavoring in carbonated beverages

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Rio Salado Community College - CHM MISC

Essay Question

1)Phosphoric acid (H₃PO₄) is used in detergents, fertilizers, toothpastes and flavoring in carbonated beverages. Calculate the percent composition of H₃PO₄. Ensure all work is shown.

 

H- 1.01 g x 3 = 3.03 g

 

P- 30.97 g x 1 = 30.97 g

 

O- 16.00 g x 4 = 64.00 g

 

3.03 g + 30.97g + 64.00g = 98.00 g

 

 

 

• Essay Question #2 - Caffeine contains by mass 49.5% C, 5.15% H, 28.9% N and 16.5% O, and the molecular mass is 195g/mol. What are the empirical and molecular formulas of caffeine? Ensure all work is shown.

 

C- 49.5 % C = 49.5 g C	49.5g C x 1 mole C/12.01g C = 4.12 mol C	4.12 moles /1.03 moles= 4
H- 5.15% H = 5.15 g H	5.15g H x 1 mole H/1.01g H = 5.10 mol H	5.10 moles/1.03 moles= 5
N- 28.9% N= 28.9 g N	28.9g N x 1 mole N/14.01g N = 2.06 mol N	2.06 moles/1.03 moles= 2
O- 16.5% O = 16.5g O	16.5g O x 1 mole O/16.00g O = 1.03 mol O	1.03 moles/1.03moles = 1