100 points! formation of an ion

aluminum is one of the most common elements in earth's crust, yet it is never found as a pure element in nature. that is, aluminum atoms are always combined with atoms of other elements, such as oxygen. an aluminum oxide compound you will recognize by its name is the gemstone called "ruby". its chemical formula is

al2o3

if every oxygen ion (combined with an aluminum ion) has a charge of -2, what must the charge of each aluminum ion be? how can you tell this? also, what has to happen to an uncharged aluminum atom so that it will bond with oxygen?

disclaimer: if the question is not answered fully or if it makes no sense it will be reported

1. +3.

2. 2 atoms each one loses 3.0 electrons and bonded to 3 O atoms (each one gain 2 electrons).

Explanation:

If every oxygen ion (combined with an aluminum ion) has a charge of -2,

1. what must the charge of each aluminum ion be? How can you tell this?

The charge of each Al ion is +3.

The Al₂O₃ is neutral. the formal charge of the molecule is zero.

∴ 2(charge of Al) + 3(charge of oxygen) = 0.

2(charge of Al) + 3(- 2) = 0.

2(charge of Al) - 6 = 0.

2(charge of Al)  = + 6.

(charge of Al) = +6/2 = +3.

2. Also, what has to happen to an uncharged aluminum atom so that it will bond with oxygen?

Al is a metal that has the tendency to lose electrons and oxygen has the tendency to gain electrons.

So, 2 atoms each one loses 3.0 electrons and bonded to 3 O atoms (each one gain 2 electrons).

"you start with 15.67 g mgco3-xh2o, when heated and all the water is removed, you are left with 7.58 g mgco3 only.

therefore, you had 15.67 - 7.58 = 8.09g h2o  

moles of each :

7.58g mgco3 = ? moles = 7.58g / 83.4g/mole = 0.09moles  

8 09g h2o = ? moles = 8.09g / 18g/mole = 0.44moles  

molar ratio between the two by dividing both numbers by the smallest number :

0.09 / 0.09 = 1  

0.44 / 0.09 = 4.8  

mgco3-5h2o"