Can someone please explain what I'm doing wrong? Balancing combination reactions.?

Question

Hi, I'm homeschooled, so I really have no way of figuring out what I'm doing wrong (since I have no teacher, and I've already surpassed my mother's knowledge of the subject).

Anyway, in chemistry I'm at the point of "completing and balancing combination reactions." Here's an example of a problem that I do not understand:

Be + O [sbscrpt2] ----> ? (I would have written simply BeO [sbscrpt2] because every atom on the left is also accounted for on the right, and I thought that that was all that's necessary.)

However, the book lists the answer as 2BeO. Where did the extra Be come from?

Thank you!!!

Ahhh! I think I may have figured it out! Is it because now that these two elements are combining to form one new substance, the O [sbscrpt2] indicates that there are not only 2 O's but also 2 Be, and therefore there needs to be two Be's on the left hand side?

Answer 1

Well since Be has a charge of 2+ and O has a charge of 2- , the only way for Be and O to balance is if one element of each is put together. Therefore,

Be + O[sbscrpt 2] ---------> BeO

and since there are 2 O's on the left side and only one on the right you would ...


Be + O[sbscrpt 2] ---------> 2 BeO

and now since there are 2 Be's on the right side and only Be on the left, you would balance it again....


2 Be + O[sbscrpt 2] ---------> 2 BeO

and that is your answer.

Answer 2

The reason that the product formed is BeO can be derived from the periodic table. Elements in Group IIA (The Alkaline Earth Metals) tend to form 2+ ions because losing two electrons gives them a valence shell with an octet (noble gas configuration). Beryllium is in group IIA, so that's what it should do. In an ionic bond, oxygen atoms tend to gain two electrons because that would give them an octet as well. Each beryllium atom has two electrons it can lose in an ionic bond, so each beryllium can only react with a single oxygen atom. However, oxygen gas is diatomic, so there are actually two oxygen atoms available. It thus takes two beryllium atoms to react with one oxygen molecule (O2), so that means beryllium will have a coefficient of two. Then, to maintain an equal number of atoms on each side of the equation, a subscript of two must be added to beryllium oxide.

Answer 3

Beryllium is a group IIA alkaline metal. As such, it loses two electrons to empty its outermost electron orbitals to form a filled shell, thus leaving the beryllium ion with a +2 charge.

Oxygen gas (O2), has two oxygen atoms. They are in group VIB, so each atom will tend to gain two electrons to form a filled shell. This means each Oxygen atom has a -2 charge.

Beryllium oxide is the product of the reaction of beryllium metal with oxygen gas. The balanced equation would be:

2 Be + O2 ====> 2 BeO

Answer 4

The complete balanced equation would be

2Be + O2 ---> 2BeO

the reason for this is you do have to have to have the same number of each element on each side. Balancing the equation doesn't mean just matching the right side to match the left but both sides to match eachother. To correctly balance an equation at the level it seems you're at you do need to be given both sides of the equation.

Answer 5

A) You need to write hydrogen as diatomic molecules: 2 Al(s) + 3H2 (g) => 2 AlH3(s) B) N is in group VA, so it has a -3 charge AlN will be produced 2 Al (s) + N2 (g) ----> 2 AlN (s)

Answer 6

Reaction is going to be:
Be + O2 ----> BeO
Now u have to balance:
2Be + O2 ----> 2BeO

I hope this helps!!