If 21.3 grams of lithium react with excess water, how many liters of hydrogen gas can be produced at 297 Kelvin and 1.40 atmospheres?

2 Li (s) + 2 H2O (l) yields 2 LiOH (aq) + H2 (g)

Can you please explain it step by step? I'm very lost with this one! Thank you

Question

If 21.3 grams of lithium react with excess water, how many liters of hydrogen gas can be produced at 297 Kelvin and 1.40 atmospheres? 

2 Li (s) + 2 H2O (l) yields 2 LiOH (aq) + H2 (g)

Can you please explain it step by step? I'm very lost with this one! Thank you

joannablackwelder · Answer

I would convert the g to moles, then use mole ratios to find the moles of hydrogen gas.

joannablackwelder · Answer

Then use the ideal gas equation to find volume.

anonymous · Answer

okay that makes since.  Does it have to be balanced? and is it?

joannablackwelder · Answer

Yes, the equation needs to be balanced. Can you tell me if it is or not?

joannablackwelder · Answer

Or at least guess?

anonymous · Answer

No the Hydrogen is off right?

joannablackwelder · Answer

Looks like there are 4 hydrogens on each side to me. Why do you think it is off?

anonymous · Answer

ohh wait its the Oxygen right? 2 on the left and 1 on the right

joannablackwelder · Answer

Because there are 2LiOH, there are two oxygens on each side.

anonymous · Answer

okay i see that now. but what about hydrogen it says 2H2O and i get that that ones 4 but isn't H2 just 2 not 4?

joannablackwelder · Answer

Yes, H2 is just 2, but there are 2 more H from 2LiOH.

joannablackwelder · Answer

So, it is balanced. I just wanted to see if you knew why. :)

anonymous · Answer

ohhhh my gosh i get it now!

joannablackwelder · Answer

:)