Balance the equation: __AgNO3+__Cu=__Cu(NO3)2+__Ag help please

Problem page gaseous ethane reacts with gaseous oxygen gas to produce gaseous carbon dioxide and gaseous water . if of water is produced from the reaction of of ethane and of oxygen gas, calculate the percent yield of water. be sure your answer has the correct number of significant digits in it.

The molality of calcium chloride (cacl2) in an aqueous solution is 2.46 m. what is mole fraction of the solute?

What mass of natural gas (ch4) must you burn to emit 276 kj of heat?