Answer:
B is the answer because it doesn't matches the num of valence electrons
Answer:
Redox type
Explanation:
The reaction is:
2Cr + 3Fe(NO₃)₂ → 2Fe + 2Cr(NO₃)₃
2 moles of chromium can react to 3 moles of iron (II) nitrate in order to produce 2 moles of iron and 2 moles of chromium nitrate.
If we see oxidation state, we see that chromium changes from 0 to +3
Iron changed the oxidation state from +2 to 0
Remember that elements at ground state has 0, as oxidation state.
Iron is being reduced while chromium is oxidized. Then, the half reactions are:
Fe²⁺ + 2e⁻ ⇄ Fe (Reduction)
Cr ⇄ Cr³⁺ + 3e⁻ (Oxidation)
When an element is being reduced, while another is being oxidized, we are in prescence of a redox reaction.
<span>1. What is the molar mass of gold?
Molar mass is a unit that expresses the mass of a molecule per one mol. The molar mass can be obtained by adding the neutron with the proton of the atoms. Gold has atomic number 79 so the proton is 79. The number of the neutron is 118. Then the molar mass would be: 79 + 118 = </span>197 g/mol<span>
</span><span>2. Calculate the number of moles of gold (Au) in the sample. Show your work.
</span>In this question, you are given the mass of the gold and asked for how many moles the sample has. To find the number of moles you just need to divide the weight by the molar mass.
For 45.39 grams of gold, the number of moles would be:
45.39 / (197g/mol)= 0.23 moles
3. Calculate the number of atoms of gold (Au) in the sample. Show your work.Moles is unit of a number of molecules but 1 mol doesn't represent 1 molecule. The number of atoms can be obtained by multiplying the number of moles with Avogadro number. The calculation would be:
0.23 moles * (6.023 * 10^23 molecules/mol)= 1.387 * 10^23 molecules
1 mole is equal to 1 moles NaOH, or 39.99711 grams.
Hope this helped
Answer:
I don't see a specific question, so I'll make a few comments and hope that answers the reason for the post.
Explanation:
Zinc(Zn) does react with iron chloride, since zinc is a more reactive metal than the iron.
When Zn is introduced to an iron (III) chloride solution, the Zn disoplaces the Fe atom in a displacement reaction.
The chemical equation of the reaction:
Zn + Fe(III)Cl3 → ZnCl3 + Fe
Energy is often realeased in this type of reaction, since the resulting chemical products have a lower energy that the reactants.
There are several metals more reactive than iron. One of the more interesting examples of a highly exothermic reaction with iron chloride (rust) is the reaction of aluminum with iron chloride. `This is highly exothermic and is labelled a thermite reaction. It provides a spectacular flame that is not enough to weld railroad tracks together.
