The reaction of iron (III) oxide and aluminum is initiated by heat released from a small amount "starter mixture". This reaction is an oxidation-reduction reaction, a single replacement reaction, producing great quantities of heat (flame and sparks) and a stream of molten iron and aluminum oxide which pours out of a hole in the bottom of the pot into sand.
The balanced chemical equation for this reaction is:
2 Al(s) + Fe2O3(s) --> 2Fe(s) + Al2O3(s) + 850 kJ/mol
Curriculum Notes
This chemical reaction can be used to demonstrate an exothermic reaction, a single replacement or oxidation-reduction reaction, and the connection between ∆H calculated for this reaction using heats of formation and Hess' Law and calculating ∆H for this reaction using qrxn = mc∆T and the moles of limiting reactant. This reaction also illustrates the role of activation energy in a chemical reaction. The thermite mixture must be raised to a high temperature before it will react.
To determine how much thermal energy is released in this reaction, heats of formation values and Hess' Law can be used.
By definition, the deltaHfo of an element in its standard state is zero.
2 Al(s) + Fe2O3(s) --> 2Fe (s) + Al2O3 (s)
The deltaH for this reaction is the sum of the deltaHfo's of the products - the sum of the deltaHfo's of the reactants (multiplying each by their stoichiometric coefficient in the balanced reaction equation), i.e.:
deltaHorxn = (1 mol)(deltaHfoAl2O3) + (2 mol)(deltaHfoFe) - (1 mol)(deltaHfoFe2O3) - (2 mol)(deltaHfoAl)
deltaHorxn = (1 mol)(-1,669.8 kJ/mol) + (2 mol)(0) - (1 mol)(-822.2 kJ/mol) - (2mol)(0 kJ/mol)
deltaHorxn = -847.6 kJ
The melting point of iron is 1530°C (or 2790°F).
MARK ME BRAINLIEST
Answer:
Electrolysis
Explanation:
The electrolysis of water is one such experiment that shows that water is made up of hydrogen and oxygen atoms only in the ratio of 2 to 1.
In the electrolysis of water, electricity is passed through acidified water to cause it to decompose.
The electrolysis of water is also known as the electrolysis of dilute tetraoxosulphate (VI) acid.
At the cathode, H⁺ ions are discharged and hydrogen gas is liberated:
2H⁺ + 2e⁻ → H₂
At the anode, both the sulfate ion and hydroxyl ions migrate to this electrode. Only the OH⁻ is selected for preferential discharge due to its lower position in that activity series.
4OH⁻ → 2H₂O + O₂ + 4e⁻
Oxygen gas is produced at the anode.
This electrolysis demonstrates the volumetric composition of water that is, 2 volumes of hydrogen at the cathode and 1 volume of oxygen at the anode.
B - Sediment . Many layers of sediment slowly built up into a rock which turn into a fossil .
