Chemical Forums
Chemistry Forums for Students => High School Chemistry Forum => Topic started by: MelissaBrown on January 02, 2010, 12:46:39 PM
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Hello, I am in grade 10 and we are doing an antacid lab.
I am very confused... well I only have 3 questions left and I don't know how to answer them?
Could someone please give me the word equation, and balanced chemical equation for Tums, Gaviscon, and Phillips. Tums contains calcium carbonate, Gaviscon has aluminum hydroxide and sodium bicarbonate, and phillips has magnesium hydroxide.
I just need the word equation and balanced chemical equation :)
Thank you! :-*
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So, its just dropping them in water?
If so:
CaCO3(s) + H2O(l) ----> CO2(g) + CaO(s) + H2O(l)
Calcium carbonate solid and water react to form carbon dioxide gas, calcium oxide solid and water.
Al(OH)3(s) + H2O(l) -----> ..
As far as I can tell, this on has no net reaction.
Mg(OH)2(s) + H2O(l) ----->
As would this one, not with water and not that I can think of.
Maybe you can tell us more specifically what they are reacting with.
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This is what we did:
Put water in an erlen meyer flask.
Put 15 drops of hydrochloric acid inside.
Put 2 drops of phenolphthalein inside, crush a tablet and put it inside.
Then we mixed it and waited three minutes, then dropped sodium hydroxide inside until the solution turned pink.
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Ok. That makes all the difference.
Oh, fun. Titration.
I'm gonna pass of phase notation for now.
Could you tell me the outcome for each of them?
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They all turned pink again, usually after 5-6 drops each.
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So, its just dropping them in water?
If so:
CaCO3(s) + H2O(l) ----> CO2(g) + CaO(s) + H2O(l)
Calcium carbonate solid and water react to form carbon dioxide gas, calcium oxide solid and water.
Al(OH)3(s) + H2O(l) -----> ..
As far as I can tell, this on has no net reaction.
Mg(OH)2(s) + H2O(l) ----->
As would this one, not with water and not that I can think of.
Maybe you can tell us more specifically what they are reacting with.
Actually, none of the three reacts with water.
CaCO3 is insoluble in water.
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The antacids are bases/alkalies and you have reacted them with HCl, an acid. The reactions are just acid-base neutralization reactions.
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Sorry, I should have been more specific.
Where there any precipitates with them? I know that all three should end up being neutral.
Well, here's a crack at it.
CaCO3 + H+ + Cl- -----> CaCl2 + OH- + 1/2 O2
One mole of calcium carbonate reacts with one mole of HCl to produce one mole of CaCl2, one mole of hydroxide ions, and 1/2 mole of oxygen gas.
Al(OH)3 + 3H+ + 3Cl-/sup] ------> AlCl3 + 3H2O
One mole of aluminum hydroxide reacts with three moles of hydrochloric acid to produce one mole of aluminum chloride and three moles of water.
Mg(OH)2 + 2H+ + 2Cl- -----> MgCl2 + 2H2O
One mole of magnesium hydroxide reacts with hydrochloric acid to produce one mole of magnesium chloride and two moles of water.
That first one doesn't seem right to me. However, the other two are quite correct.
Actually, none of the three reacts with water.
CaCO3 is insoluble in water.
Quite right. I mistook it with sodium bicarbonate
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The antacids are bases/alkalies and you have reacted them with HCl, an acid. The reactions are just acid-base neutralization reactions.
Which they followed up with a titration. Sounds like a fun experiment.
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CaCO3 + H+ + Cl- -----> CaCl2 + OH- + 1/2 O2
One mole of calcium carbonate reacts with one mole of HCl to produce one mole of CaCl2, one mole of hydroxide ions, and 1/2 mole of oxygen gas.
That first one doesn't seem right to me. However, the other two are quite correct.
Oxygen gas is not evolved. Try that first equation again.
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CaCO3 + H+ + Cl- -----> CaCl2 + OH- + 1/2 O2
One mole of calcium carbonate reacts with one mole of HCl to produce one mole of CaCl2, one mole of hydroxide ions, and 1/2 mole of oxygen gas.
Forgot carbon..
CaCO3 + 2H+ + 2Cl- -----> CaCl2 + CO2 + H2O
HA! GOT IT!
One mole calcium carbonate reacts with two moles hydrochloric acid to produce calcium chloride, carbon dioxdie and water.
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CaCO3 + H+ + Cl- -----> CaCl2 + OH- + 1/2 O2
One mole of calcium carbonate reacts with one mole of HCl to produce one mole of CaCl2, one mole of hydroxide ions, and 1/2 mole of oxygen gas.
Forgot carbon..
CaCO3 + H+ + Cl- -----> CaCl2 + CO2 + OH-
Yeah, that's as much of it as I can get.
Why did you leave that equation with ions? Finish it
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Why did you leave that equation with ions? Finish it
Got it now. Takes me a bit sometimes. I don't know why that one threw me off so much. Maybe it was all the C's..
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Yes. That's right. :)
Good job
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Oh my gosh :) Well thank you, but our teacher emailed the class about 10 minutes ago with the NEW work sheet (she said she might send us a new one)
And now, it just says:
Write down the chemical equation for each antacid, WITH HYDROCHLORIC ACID.
::)
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Very nice.
Just remember that strong acids are written as free flowing ions, so
H+(aq) + Cl-(aq)
is just as correct as
HCl(aq)