Question

thermite is a mixture of iron (iii) oxide and aluminum powders that was once used to weld railroad tracks. it undergoes a spectacular reaction to yield solid aluminim oxide and molten iron.

how many atoms of aluminum react for every 1.00g aluminum oxide that forms?

Answer 1

First of all you'll need to know the formula for aluminium oxide Al2O3. This has a formula weight of 102 grams per mole. So 1g represents 0.01 moles, roughly speaking. There are 6.022e23 molecules per mole so about 6e21molecules or 1.2e22 aluminium atoms. (Please note I've used engineering notation for Avogadro's number, which is 6.022 times ten to the power of 23 molecules per mole).

Answer 2

more clearly please

Answer 3

I've converted the 1g of aluminium oxide into moles by dividing by the formula weight of aluminium oxide, which is 102g/mole. This amount is useful because there is a constant number of molecules per mole - this is called Avogadro's number. You can use this to calculate how many molecules there are in the fraction of a mole in question. The number of molecules can be converted to the number of aluminium atoms by multiplying by the number of aluminium atoms per molecule. I hope this helps, E

Answer 4

can you show me the formula

Answer 5

\[ Al + Fe2O3\rightarrow Al2O3 + Fe\] This almost doesn't matter as long as you know that you get Al2O3 out of the reaction. The question is all about the product and it tells you there is 1g of the product in the question.