Questions asked by AMorri

• Back to user's profile
• When 1.64 g sample of an unknown hydrocarbon was completely burned in oxygen, it produced 2.36 g of H2O. What is the percentage by mass of carbon in this hydrocarbon?
  
• What is the concentration of sodium ions in a solution obtained by dissolving #"3.25 g"# of sodium phosphate, #"Na"_3"PO"_4#, in enough water to make #"250.0 mL"# of solution?
  
• What is the molarity of the oxalic acid (H2C2O4) solution that required 18.29 mL of a 1.75 x10–2 M aqueous solution of NaOH to completely neutralize a 20.00 mL sample of H2C2O4?
  
• Given the thermochemical equation Al2O3(s) → 2Al(s) + (3/2)O2(g) ∆Hº = 1676 kJ/mol what is ∆Hº for the reaction? 4Al(s) + 3O2(g) → 2Al2O3(s)
  
• How much energy is required to ionize an He^+ ion in its ground state?
  
• How do I simplify the trigonometric function? sin4(α) − cos4(α) + cos2(α)
  
• How do I simplify the trigonometric expression? cos(x)/sec(x) + tan(x)
  
• How do I do this?
  
• How do I do this?
  
• How do I do this? #DeltaH_(rxn) = -"2219.9 kJ/mol propane"#, so how much heat is released by combustion of #"16.50 kg propane"#?