Determining the Best composition for Thermite

we know that in the thermite combustion reaction, fine aluminum powder reacts with rust to form molten iron metal and a lot of heat.

the chemical name for rust is iron(2) oxide and is written like Fe2O3.

let's write it in a chemical equation;

Al(s) + Fe2O3(s) -----> Fe(s) + Al2O3(s)

before we can do any chemistry work, we need our chemical equations to be balanced; let's get them balanced;

2Al(s) + Fe2O3(s) -----> 2Fe(s) + Al2O3(s)

now the number of atoms of each element on both sides are equal hence the equation is balanced.

the atomic mass of aluminum is 27 which means every mole of aluminum atoms will have a mass of 27 grams.there are two moles of aluminum in the balanced chemical equation hence the net mass of aluminum required for thermite is 54 grams.

similarly, the molecular mass of rust is 160 grams, which is also the net mass of rust required for this composition.

now we compare the ratios of the reactants required to make thermite;

54 : 160

the above is the ratios of masses of reactants required to make a working composition of thermite, to make matters more simple, let's convert it into percentage;

54+160=214

 (54/214)x100% : (160/214)x100%

25% : 75%

from the above calculation, we can state that for every 100g batch of thermite, 25g of aluminum powder and 75g of rust are required.

aluminum foils are readily available and can be crushed into powder form and rust can be manufactured through electrolysis and other means.

thermite can easily be prepared at home for experimentation purposes.

the method described here is applicable for other compositions as well incl. composition for black powder (medieval gun powder).

image source : google.com

thermite is also the hottest burning man-made substance there is,it burns at about 2500*C.
a thing to note is that there is no gaseous product in this reaction, hence there is nothing to be evaporated.it means that all of the energy is released as heat and none is absorbed to evaporate.