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Chemistry Forums for Students => High School Chemistry Forum => Topic started by: maisy on November 10, 2004, 02:37:02 PM

Title: balanced equations
Post by: maisy on November 10, 2004, 02:37:02 PM
I am new to this so please bear with me.  I need to write a balanced equation for the following.  When Aluminum Hydroxide reacts with Hydrochloric Acid, a neutralization reaction occurs with water and an Aluminum Salt as the products.  Consider the reaction of 234 g of Aluminum Hydroxide with excess Hydrochloric Acid.  I need to write a balanced equation and answer some other questions but I can do that but am having trouble with balanceing first.  This is what I have so far, could someone please tell me if I did it correctly.

Al(OH)3 + 3HCL --- AlCL3 + 3HOH

Thanks
Title: Re:balanced equations
Post by: Donaldson Tan on November 10, 2004, 04:29:57 PM
your equation is correct. water is however written commonly as H2O.

since you have the equation and the stoichiometric ratio now, you should be able to work out the solution for the rest of the questions
Title: Re:balanced equations
Post by: anlb4 on November 14, 2004, 02:56:03 PM
In response to the above balanced equation would the moles of the known be:

M al(oh)3  = 234g/78g al(oh)3 = 3 Moles of al(oh)3

or

M  Nal(oh)3 = 234g/46 = 5.09

 The known is 234 grams of aluminum hydroxide with excess HCL

I thought the first one my girlfriend the second are either one of us right?
Title: Re:balanced equations
Post by: anlb4 on November 15, 2004, 09:03:16 AM
I am still wonderin g about my reply to this equation,
Title: Re:balanced equations
Post by: AWK on November 15, 2004, 10:14:16 AM
For 3 moles of Al(OH)3 you need 9 moles of HCl and you will obtain 3 moles of AlCl3 (= 3 x 133.5 g of AlCl3)
But what does mean 46 - I do not understand

AWK
Title: Re:balanced equations
Post by: anlb4 on November 15, 2004, 10:50:12 AM
Our chemistry teacher has taught us differently I guessWe need to find the moles of the known in the above prblem that maisy wrote in about, we balance the equation , and now have to find the mole of the known, we were told to take moles of known, 234g of al(oh)3 (aluminumn hydroxide with excess hcl?) divided by grams of known.  aluminum, oxygen and hydrogen.= 78...3 oxygen 3 hydrogen, which equals the moles of the known, I guessed I am confused ...could you help
Title: Re:balanced equations
Post by: Donaldson Tan on November 15, 2004, 04:00:39 PM
the reaction equation tells us how many moles of HCl reacts with how many moles of Al(OH)3 to produce how many moles of AlCl3 and H2O. Hence, we can derive the molar ratio of a product to a reactant, and therefore calculate how much product is formed from a known quantity of reactant used up.