kieraguarnieri

i have no idea how to find the number of moles

Help! H2 is produced by the reaction of 121.9 mL of a 0.8995 M solution of H3PO4 according to the following equation. 2 Cr + 2 H3PO4→ 3 H2 + 2 CrPO4 (a) Determine the number of moles of H2. mol (b) Determine the mass (in g) of H2. g Molecules of I2 are produced by the reaction of 0.4544 mol of CuCl2 according to the following equation. 2 CuCl2 + 4 KI → 2 CuI + 4 KCl + I2 (a) How many molecules of I2 are produced? (b) What mass (in g) of I2 is produced? g 2) A compact car gets 29.4 miles per gallon on the highway. If gasoline contains 65.8% carbon by mass and has a density of 0.7715 g/mL, determine the mass (in kg) of carbon dioxide produced during a 500. mile trip. kg 3)Potassium permanganate, a strong oxidizing agent, is commonly used in titrations because of its significant purple hue in solution. An experiment was performed in which a sample of iron(II) chloride (FeCl2) was dissolved in water and titrated with potassium permanganate (KMnO4) according to the following balanced equation. KMnO4(aq) + 8 HCl(aq) + 5 FeCl2(aq) → MnCl2(aq) + 5 FeCl3(aq) + 4 H2O(l) + KCl(aq) If 28.11 mL of 0.1145 M KMnO4 was added to the solution to reach the end point, what mass of FeCl2 was in the sample? g FeCl2 4)A sample of 0.54 g of carbon dioxide was obtained by heating 1.38 g of calcium carbonate. What is the percent yield for this reaction? CaCO3(s) → CaO(s) + CO2(s) % 5)20.0 g of aluminum and 246 g of chlorine gas react until all of the aluminum metal has been converted to AlCl3. The balanced equation for the reaction is the following. 2 Al(s) + 3 Cl2(g) → 2 AlCl3(s) What is the quantity of chlorine gas left, in grams, after the reaction has occurred, assuming that the reaction goes to completion? (The formula mass of aluminum metal, Al, is 26.98 g/mol, and the formula mass of chlorine gas, Cl2, is 70.90 g/mol.) g 6) What volume (in mL) of 0.0151 M HBr solution is required to titrate 125 mL of a 0.0126 M Ca(OH)2 solution? Ca(OH)2(aq) + 2 HBr(aq) → CaBr2(aq) + 2 H2O(l)