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NoelGrecoBest ResponseYou've already chosen the best response.0
For someone to comment, he's have to know more about the lab.
 one year ago

aaronqBest ResponseYou've already chosen the best response.1
the moles you can simply find by dividing the masses by their molar mass... for the volume of H2 formed, you need to write the equation of the reaction in your exp and work with that.
 one year ago

eli123Best ResponseYou've already chosen the best response.0
@aaronq so for magnesium it would be 24.31/0.035?
 one year ago

eli123Best ResponseYou've already chosen the best response.0
oh ok and for h2? @aaronq
 one year ago

aaronqBest ResponseYou've already chosen the best response.1
you have to find the volume first
 one year ago

eli123Best ResponseYou've already chosen the best response.0
is the volume of hydrogen gas produced the same as teh volume of liquid displaced? @aaronq
 one year ago

aaronqBest ResponseYou've already chosen the best response.1
unless you made other gases in your experiment
 one year ago

eli123Best ResponseYou've already chosen the best response.0
so the volume divided by the mass of h2 will give me the moles of h2?
 one year ago

aaronqBest ResponseYou've already chosen the best response.1
well for ideal gases you can just use the fact that 1 mole = 22.414 L at STP
 one year ago

aaronqBest ResponseYou've already chosen the best response.1
otherwise you have to know the density of the gas
 one year ago

eli123Best ResponseYou've already chosen the best response.0
therefore, how would the equation look?
 one year ago

aaronqBest ResponseYou've already chosen the best response.1
so for ideal gases, moles = volume of gas/(22.414 L/mol)
 one year ago

aaronqBest ResponseYou've already chosen the best response.1
make sure you have the same units
 one year ago

eli123Best ResponseYou've already chosen the best response.0
@aaronq for the moles of magnesium igot 0.001 for all the trials, but my friend wrote it in dimensional analysis . whats betteR?
 one year ago

aaronqBest ResponseYou've already chosen the best response.1
it's the same thing, since it's a gas, the volume is proportional to the amount of moles
 one year ago

eli123Best ResponseYou've already chosen the best response.0
ok and how would i find the ratio of volume displaced in mL to moles h2 gas produced? @aaronq
 one year ago

aaronqBest ResponseYou've already chosen the best response.1
a ratio is just a division volume of gas/moles of gas
 one year ago

eli123Best ResponseYou've already chosen the best response.0
so volume of h2/moles of h2?
 one year ago

eli123Best ResponseYou've already chosen the best response.0
@aaronq i get a huge number
 one year ago

aaronqBest ResponseYou've already chosen the best response.1
yep, thats what the want
 one year ago

aaronqBest ResponseYou've already chosen the best response.1
they actually want the volume displaced/molesof H2 which is the same thing
 one year ago

aaronqBest ResponseYou've already chosen the best response.1
to what they're asking you, yes
 one year ago

eli123Best ResponseYou've already chosen the best response.0
but its such a big number? @aaronq
 one year ago

aaronqBest ResponseYou've already chosen the best response.1
yep thats not that big of a number, remember it's in mL ..
 one year ago

aaronqBest ResponseYou've already chosen the best response.1
lol that's not a lot, it really should be around 22.414 L
 one year ago

aaronqBest ResponseYou've already chosen the best response.1
well unless they want you to calculate using Mg (s) + HCl > H2 + MgCl (aq)
 one year ago

aaronqBest ResponseYou've already chosen the best response.1
this would be the theoretical way you balance the equation and use diminutional analysis, but really your answer is gonna be like off by very little, also, because of rounding
 one year ago

aaronqBest ResponseYou've already chosen the best response.1
did they give you the concentration of the acid?
 one year ago

eli123Best ResponseYou've already chosen the best response.0
all we had to do was place a piece of magnesium inside a buret that contained hcl and this was then converted and all the hcl migrated down to the bottom of the buret
 one year ago

eli123Best ResponseYou've already chosen the best response.0
basically the magnesium was reacting with the hcl
 one year ago

eli123Best ResponseYou've already chosen the best response.0
and after that we had to find the values in that table
 one year ago

aaronqBest ResponseYou've already chosen the best response.1
hm well they really wouldn't need to tell you, do you know what a limiting reagent is?
 one year ago

aaronqBest ResponseYou've already chosen the best response.1
yep, it's the same thing. you could use the number of moles of that and translate it to moles of H2 produced 2Mg (s) + 2HCl > H2 + 2MgCl (aq) 0.001439 moles of Mg/2 = x moles of H2/1 moles of H2 = 0.0028794734677088 thats the theoretical yield
 one year ago

eli123Best ResponseYou've already chosen the best response.0
well that makes more sense because thats what we are currently learning in class haha
 one year ago

aaronqBest ResponseYou've already chosen the best response.1
oh wait sorry i multiplied, it should be moles of H2 = 0.0007198683669272
 one year ago

aaronqBest ResponseYou've already chosen the best response.1
haha oh true, well maybe let me know next time? haha
 one year ago

eli123Best ResponseYou've already chosen the best response.0
so in other words, to find lets say trial #1
 one year ago

eli123Best ResponseYou've already chosen the best response.0
where the volume of hydrgen gas produced was 37.00mL and the moles of h2 gas produced were 0.002 mol
 one year ago

aaronqBest ResponseYou've already chosen the best response.1
you would convert the mass of Mg to moles then using the balanced equation, build a relationship between H2 and Mg using their respective coefficients.. this just means: moles of Mg/coefficient=moles of H2/coefficient
 one year ago

eli123Best ResponseYou've already chosen the best response.0
moles of mg that reacted?
 one year ago

aaronqBest ResponseYou've already chosen the best response.1
yeah because thats your limiting reactant..
 one year ago

aaronqBest ResponseYou've already chosen the best response.1
for Mg is 2 for H2 is 1
 one year ago

aaronqBest ResponseYou've already chosen the best response.1
wait no i balanced it wrong because it's Mg + 2HCl > MgCl2 + H2
 one year ago

aaronqBest ResponseYou've already chosen the best response.1
so it's coefficient is 1 for both
 one year ago

aaronqBest ResponseYou've already chosen the best response.1
sorry, i'm like lost today idk why
 one year ago

aaronqBest ResponseYou've already chosen the best response.1
Mg (s) + 2HCl > H2 + MgCl2 0.001439 moles of Mg/1 = x moles of H2/1 moles of H2 = 0.001439 thats the theoretical yield which is close to what you would get if you just divided the volume of gas produced by 22.414 L
 one year ago

eli123Best ResponseYou've already chosen the best response.0
but what value would i put?
 one year ago

aaronqBest ResponseYou've already chosen the best response.1
i would go with the theoretical since thats what you're doing in class
 one year ago

aaronqBest ResponseYou've already chosen the best response.1
yeah, even round up to 0.0015
 one year ago

eli123Best ResponseYou've already chosen the best response.0
ok wait where did the 0.001439 come from>?
 one year ago

aaronqBest ResponseYou've already chosen the best response.1
its the number of moles of magnesium
 one year ago

eli123Best ResponseYou've already chosen the best response.0
ooooh yes thats my 0.001
 one year ago

aaronqBest ResponseYou've already chosen the best response.1
haha yep, i mean round to whatever you think it's best, or whatever they're teaching you at school
 one year ago

eli123Best ResponseYou've already chosen the best response.0
but for the ratio isnt moles of h2 divided by moles of magnesium? so 0.002h2/0.001mg
 one year ago

eli123Best ResponseYou've already chosen the best response.0
ratio of volume displaced to moles h2 gas prodced
 one year ago

aaronqBest ResponseYou've already chosen the best response.1
well the amount of moles of H2 produced is equal to the moles of Mg that reacted according to the stoichiometric ratios of the equation... so to answer your question it would be 37 mL/0.001 moles.. which is what you had before, if i remember correctly
 one year ago

eli123Best ResponseYou've already chosen the best response.0
37 being the volume of hydrogen gas produced and 0.001 moles of magnesium reacted?
 one year ago

aaronqBest ResponseYou've already chosen the best response.1
well, technically yes, but the question is asking for the volume displaced divided by the moles of H2 produced..which are the same values
 one year ago

eli123Best ResponseYou've already chosen the best response.0
oh so volume of liquid displaced divided by the moles of h2
 one year ago

aaronqBest ResponseYou've already chosen the best response.1
that they're asking you for in the question yes. They're basically seeing how close that value is to the ideal gas constant volume of 1 mole =22.414 L, since 37mL/0.0014 mol = 26428.5714285714285714 mL/mol 26.428 L/mol so it's close if you use more than 0.001, which i think you should do lol
 one year ago

eli123Best ResponseYou've already chosen the best response.0
oh my i get the big number again hahaha
 one year ago

aaronqBest ResponseYou've already chosen the best response.1
your friend in the other thread used 0.00144 moles
 one year ago

eli123Best ResponseYou've already chosen the best response.0
0.0014 is in the correct significant figures? i keep using 0.001
 one year ago

aaronqBest ResponseYou've already chosen the best response.1
hm idk though if you don't use that your error is pretty large
 one year ago

eli123Best ResponseYou've already chosen the best response.0
but look when i divide 0.035/ 24.31
 one year ago

eli123Best ResponseYou've already chosen the best response.0
and the right sig figures are four so you round it to 0.001?
 one year ago

aaronqBest ResponseYou've already chosen the best response.1
zeros dont count though
 one year ago

aaronqBest ResponseYou've already chosen the best response.1
well zeros on the left side
 one year ago

eli123Best ResponseYou've already chosen the best response.0
so now its 3 sig figures?
 one year ago

aaronqBest ResponseYou've already chosen the best response.1
i would use 2 sig digits b/c 0.035 .. and have 0.0014
 one year ago

eli123Best ResponseYou've already chosen the best response.0
so only 14 are significant
 one year ago
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