[brittanynf]

Lithium vigorously reacts with water at STP according to the following equation: 2Li(s)+2H2O(aq)----> 2LiOH(aq) +H2(g). If 0.1331 g of solid Lithium reacts with 1.50 L of water, how many liters pf H2 will be produced assuming STP?

[Borek]

How many moles of Li? How many moles of hydrogen produced? What is volume of 1 mole of gas at STP?

[AWK]

Lithium metal reacts quite slowly with water, not vigorously

[Schrödinger]

@ AWK : I beg to differ.
I saw this on youtube : http://www.youtube.com/watch?v=8ypUVpwgcAA. It is quite a vigorous reaction, but definitely less so than other alkali metals

[AWK]

I doubt if water had STP temperature in this experiment.

[Schrödinger]

Wiki says the lithium-water reaction at normal temperatures is brisk, but not violent. I guess we're standing on the border that divides 'vigorous' and 'non-vigorous' reactions

[408]

The video used powdered Li.  With a lump of Li the reaction is about the same as with calcium, but perhaps a bit milder.  Stick lithium does not catch fire when added to water.

[brittanynf]

seriously people, all I needed was how to solve it. not to correct the freaking reality of the question. Our teacher makes them up to have us solve problems to see if we understand the material. Its an intro class.

thanks anyways, I figured it out last night.

[brittanynf]

you helped a lot borek, thanks 

[Thujone]

Lithium vigorously reacts with water at STP according to the following equation: 2Li(s)+2H2O(aq)----> 2LiOH(aq) +H2(g). If 0.1331 g of solid Lithium reacts with 1.50 L of water, how many liters pf H2 will be produced assuming STP?

STP, 1 mole of any gas = 22.4L.  so...     1.5L/22.4L/mole= .067 mole H20
                                                            0.1331g Li / 6.94g/mole Li = .019 mole Li= limiting reactant (stoich ratio =1/1)
(2 mole Li=1 mole H2)  so.. .019 mole Li = 0.0095 mole H2 x 22.4L/mole = .2128 L H2

[sjb]

Fortunately, still the right answer, but what is the state of water at STP?

[Thujone]

Fortunately, still the right answer, but what is the state of water at STP?

Ah..saved by the other reagent.  Thank you for keeping me on my toes.