Heat Reaction

The combustion of butane produces heat according to the equation 2C4H10(g) + 13O2(g) --> 8CO2(g) + 10H2O(l) deltaHrxn= -5314kJ How many grams of butane must be burned to release 6375kJ of heat?

At pH 6.00 and pE 2.60, what is the concentration of Fe2+ (mol/L) in equilibrium with Fe(OH)3?

At pH 6.00 and pE 2.60, what is the concentration of Fe2+ (mol/L) in equilibrium with Fe(OH)3? Hint: Use the Nernst equation and the Ksp for the solubility of solid iron (III) hydroxide. I would like to know how to set up the Nernst equation and where it is appropriate to plug in the valvue and how it correlates wo the concentration. I also would like a step by step directions and the constants (such as the ksp) used. Thanks. NOTE: Moved from Environmental Studies to Chemistry

chemical reactions

Why when heating and cooling three different separate substances in open containers does the mass change in two of them(one loss mass; the other gained mass) but stays the same in the third when it is known that mass is conserved in chemical reactions? Would it be because one gave off vapor, the second melted and the third was a solid that wasn't heated enough to give off vapor or melt?

Single Replacement Reactions

Complete the balanced equation if a reaction will occur. State "does not occur" if the reaction will not take place. a. Na + H(NO3) ---> b. Ni(II) + Cu2O --> c. Zn + Mg(NO3)2 -->

center of mass

Hi-please explain steps taken to establish the center of mass with polar covalent bonds and dipole moments - why is this important?