chemistry help.10 points?
by admin on Aug.31, 2009, under Chemistry
Lynn72907 asked:
48.A 250 mL glass of orange juice contains 30.0 mg of riboflavin, C17H20N4O6. What is the
molarity of the riboflavin in this glass?
48.A 250 mL glass of orange juice contains 30.0 mg of riboflavin, C17H20N4O6. What is the
molarity of the riboflavin in this glass?
49.Iron(III) chloride can be produced by reacting Fe2O3 with a hydrochloric acid solution. How many milliliters of a 6.00 M HCl solution are needed to react with excess Fe2O3 to produce 16.5 g of FeCl3?
50.Muriatic acid is often used to remove rust. A solution of muriatic acid, HCl, reacts with Fe2O3 deposits on industrial equipment. How many liters of 5.50 M HCl would be needed to react completely with 439 g Fe2O3?
Glen
September 2nd, 2009 on 4:09 pm
Monica
moles = 0.0300 g / 376.3678 g/mol= 7.97 x 10^-5
M = 7.97 x 10^-5 / 0.250 L=3.19 x 10^-4
Fe2O3 +6 HCl >> 2 FeCl3 + 3 H2O
moles FeCl3 = 16.5 g / 162.206 g/mol=0.0102
moles HCl = 0.0102 x 6 / 2 =0.0306
V = 0.0306/ 6.00 M= 0.0051 L =>5.1 mL
moles Fe2O3 = 439 g/159.694 g/mol= 2.75
moles HCl = 2.75 x 6 =16.5
V = 16.5 / 5.50 M=3.0 L