<span>d. filters out harmful ultraviolet radiation</span>
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
The concentration of cell is less than that of the solution .
Hence the cell will be called as hypotonic and the solution will be called as hypertonic.
in order to balance the concentration on the two sides of cell (inside and outside in the solution) there will be movement of solvent particles (through semipermeable membrane ) from cell (lower concentration of solute) to solution (higher concentration of solute).
Thus cell will shrink.
I think the answer is C. 02
Answer:
1)If I mixed salt in water I would expect the salt to: dissolve.
2) If I mixed starch in water I would expect the starch to: remain undissolved.
Explanation:
Hello,
In this case, since salt, which is commonly known as sodium chloride (NaCl) is an ionic compound, it is very likely to get dissolved in water, therefore, we would expect the salt to dissolve and form a liquid solution.
Moreover, since start is mainly composed by C-C, C-O and C-H bonds which are nonpolar, it we can say it is usually insoluble in water, therefore we will expect starch to remain undissolved but undergoing a process called gelatinization in which a suspension in formed until a slightly solid consistency.
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