To know the answer, compare the oxidation number of the element in the reactant and the product side. The oxidation number of Al was originally +3, then became 0 after the reaction. On the other hand, Fe was originally 0, then became +2 after the reaction. When the element is oxidized, it oxidation number increases. <em>Thus, the element oxidized is Fe.</em>
Answer:
0.99 pounds
2,000 oz
0.423 cups
Explanation:
In order to convert this units we need to look up their equivalences.
1 g equals 0,0022 pounds approximately
Then we need to cross-multiply:
450 g equals 0.99 pounds approximately
We can do the same calculation for the other 2 ingredients
1 g equals 16 oz
Then (125 g x 16 oz) / 1 oz = 2,000 oz (or 500 4 oz)
1 cup equals 236.59 ml
Then (100 ml x 1 cup)/ 236.59 = 0.423 cups
There are some standard numbers that help us describe the structure of an atom and help us categorize them. Those are the atomic number, the mass number and the numbers of electrons in an atom (or ion). Atoms are electrically neutral, hence they have the same number of protons as electrons. If an atom has a charge and has thus become an ion, it is because electrons joined it or left. For example in this case, since the ion has +2 charge, 2 electrons left it and thus the ion has 4 electrons (2 electrons less than its protons). The mass number is the sum of the protons and neutrons of an atom (that are in the nucleus). In this case, this yields a mass number of 13 for this ion. The atomic number of an atom (or ion) is the total number of protons in the nucleus. Protons do not leave the nucleus except for radioactive reactions and thus the atomic number of an atom (or ion) does not change in chemical reactions. In this case, the ion has an atomic number of 6.
<span>Enthalpy
change is the total heat that is absorbed or evolved in a certain reaction that
is being carried in a constant pressure system. It can be calculated by the
product of the specific heat of the substance and the difference of the final
temperature and the initial temperature. For this case, the enthalpy of combustion is given, so we simply multiply the amount of octane present to the enthalpy given to determine the total heat that is released.
Heat = 75 g ( 1 mol / 114.23 g ) (- 5500 kJ / mol ) = - 3611.14 kJ
The negative sign in the calculated value represents that this heat is being released in the process.</span>
Solubility
product constants are values to describe the saturation of ionic compounds with
low solubility. A saturated solution is when there is a dynamic equilibrium
between the solute dissolved, the dissociated ions, the undissolved and the
compound. It is calculated from the product of the ion concentration in the
solution. For the base, Ca(OH)2, the dissociation would be as
follows:<span>
Ca(OH)2 = Ca2+ + 2OH-
So, the expression for the solubility product constant would be as follows:
Ksp = [Ca2+] [OH-]^2
let x be the concentration of the Ca2+. So,
</span>
Ksp = [x] [2x]^2
<span>Ksp = 4x^3
You have to substitute the value of the concentration of the calcium hydroxide in the final expression which is not given in the problem statement in order to evaluate Ksp.
</span><span>
</span>
