posted by john .
a) why should you use moles in stoichimetric problems?
b) solid reacts violently with water, producing heat, hydrogen gas, and sodium hydroxide. how many molecules of hydrogen gas are formed when 48.7 g of soodium are added to water?
2Na + 2H2P ------> 2NaOH + H2
a)because reactions occur by mols.
b) You have the equation.
Convert g Na to mols.
Convert mols Na to mols H2 gas using the coefficients in the balanced equation.
Convert mol H2 to molecules remembering that 1 mol of a gas contains 6.02 x 10^23 molecules. Post your work if you need addition help.
i still don't get what to do for b
John--I have worked several of these problems for you over the last 2-3 weeks. You need to learn to do these. I gave you instructions in my first response. Tell me what it is about the first step; i.e., convert g Na to mols Na.