Brandy Said:

Help with classifying chemical reactions and balancing chemical equations?

We Answered:

Have a look at:

Formulae: http://www.fordhamprep.org/gcurran/sho/s…
http://www.syvum.com/cgi/online/serve.cg…

Balancing : http://richardbowles.tripod.com/chemistr…

Sara Said:

Balancing Chemical equations..10th grade Chem..help please.?

We Answered:

1) Which element gets the numbers that come after the parenthesees..for example the begining is Ca(OH)2 ... Does the 2 go to the O and the H or to the Ca???

the 2 stands for 2 of whatever is inside the parentheses
Ca(OH)2 stands for 1 Ca & 2 (OH)'s ,,, that's 2 O's & 2 H's
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2) On the part with Ca(NO3)2 I know I have to multiply but do I multiply the 3 inside the parenthesees and the two, or does the two only go to the Ca...
the 2 goes only for what is in the parentheses... 2 (NO3)'s
===================================

since ca(NO3)2 has 2 (NO3)'s we need to double the HNO3:
Ca(OH)2 + _2 HNO3 ---> __Ca(NO3)2 + __H2O

since there are 2 O's in the 2 OH's we can make 2 waters:
Ca(OH)2 + 2 HNO3 ---> __Ca(NO3)2 + 2 H2O

done

=================

p.s. sometimes it helps to think of water as being H-OH , instead of H2O

then it is easier to see that Ca(OH)2 's 2 OH's can make 2 waters "H-OH"
& that they will also use up the 2 H's from the 2 HNO3's

Tamara Said:

How do you balance chemical word equations?

We Answered:

Like a baseball game, it helps to have a scorecard. In other words, what do the words mean when it comes to describing compounds. Once you have surmounted this barrier, balancing follows.

Start with "aluminum bromide". If you look it up, it is AlBr3. Why? Aluminum can shed 3 outer electrons to form an Al+3 ion and Br (which, as an element, exists as a dimer, Br-Br), can "suck up" one electron per atom to form Br-. Chlorine is also a dimer (Cl-Cl). However, Cl is more adapt at "sucking up" electrons than is Br, so it can boot the Br- out of the compound, take its electron, and leave a Br atom (which rapidly reacts with another unhappy Br that has been booted out). This may sound silly, but it is about what happens, and leads us to balance. The conversion to compounds and dimers leads to....
AlBr3 + Cl2 -> AlCl3 + Br2
Balancing an equation simply means that every atom on one side is accounted for on the other. Here, the chlorines and bromines are out of balance. So how do we even them out?? Well, if we double the AlBr3 (and we have to double the whole compound, and not just one part), we get 6 bromines on the left. Since the bromine winds up in a dimerized form, for those 6 bromines, they can be balanced by 3Br2. The same deal with Chlorine. So then, we have
2 AlBr3 + 3 Cl2 -> 2 AlCl3 + 3Br2.

On to #2. The sulfuric acid (H2SO4) serves to oxidize elemental copper to the +2 state. Some of the acid provides SO4-2 ion for the copper salt. However, if something goes "up" in oxidation state, something else goes "down". And that something is the "S" in H2SO4, which drops from +6 oxidation to +4 oxidation in SO2.
The rules of oxidation states is pretty easy. Elements are 0, hydrogen in a compound is +1 and oxygen is -2. Compounds have to be overall 0. There are exceptions, but not too many to worry about at this stage.

In this mess, some additional water is formed, since we have to do something with the 4Os in each molecule of H2SO4; 2 wind up in SO2, the other 2 wind up in water. So lets try to balance this
Cu + H2SO4 -> CuSO4 + SO2 + H2O
For starters, we need more H2SO4 per atom of Cu. Lets double it to get...
Cu + 2H2SO4 -> CuSO4 + SO2 + H2O.
Looks better,but doubling the H2SO4 means we have 4H on the right and 2 on the left. Also, we have 8O on the left and seven on the right.
So lets double the amount of water formed.....
Cu+ 2H2SO4 -> CuSO4 + SO2 + 2H2O
Hopes this helps.

Laurie Said:

Balancing Chemical Word Equations?

We Answered:

First, find the symbols for your reactants and your products:
Zinc metal = Zn
Hydrochloric acid = HCl
Hydrogen gas = H2
Zinc Chloride = ZnCl2

Then, put the equation together.
Zn + HCl ---> H2 + ZnCl2

Next, balance out the hydogens and chlorines by placing a coefficient of 2 in front of HCl.
Zn + 2HCl ---> H2 + ZnCl2

I hope this helps!:)

Jo Said:

Balancing chemical equations help?

We Answered:

V2O5 + 5CaS ? 5CaO + V2S5

The vanadium is balanced already. To pick up all 5 oxygen atoms, you will need 5 Ca atoms. You also need 5 S atoms on the left.

Jeanette Said:

I need someone to help me with my chemistry homework ASAP! Who knows about balancing chemical equations? HELP!?

We Answered:

http://www.webqc.org/balance.php

Balance calculator, works every time. Just type in the full equation and you're done, it comes in handy for those tricky ones or when you're just too lazy to do them lol