Answer:
Explanation:
The half reactions are:
Mg → Mg²⁺ + 2e⁻
2H⁺ + 2e⁻ → H₂
The first equation is an oxidation half while the second is a reduction half. To get the overall reaction equation, we simply combine the two equations. The reactants combines at the left hand side with the products comes together at the right hand side.
Mg + 2H⁺ + 2e⁻ → Mg²⁺ + 2e⁻ + H₂
Now we cancel out the species that appear on both sides:
Mg + 2H⁺ → Mg²⁺ + H₂
The equation is already balanced !
Answer:
42.3%
Explanation:
By the reaction given the stoichiometry between MnO₄⁻ and Fe⁺² is 1 mol of MnO₄⁻ to 5 moles of Fe⁺². When KMnO₄ dissolves, it forms the same amount of K⁺ and MnO₄⁻ (1:1:1), so the number of moles of MnO₄⁻ used is:
n = Volume*concentration
n = 0.0216 L * 0.102 mol/L
n = 2.20x10⁻³ mol
1 mol of MnO₄⁻ -------------------- 5 moles of Fe⁺
2.20x10⁻³ mol ---------------------- x
By a simple direct three rule
x = 0.011 mole
The molar mass of iron is 55.8 g/mol. The mass is the molar mass multiplied by the number of moles, thus:
m = 55.8*0.011
m = 0.614 g
Then, the percent of iron in the ore is:
(mass of iron/ mass of ore) *100%
(0.614/1.45)*100%
42.3%
Hey there!
500 mg of protein is present in 100 mL of solvent as per the concentration 0.5 mg/mL or 500 g/mL ,
So, 250 mg (0.25 g) of serving food need to be added to 100 mL solvent in order to prepare 50 mg of protein/100 mL solution.
Dilution factor = initial amount of protein / final amount of protein
= 6 g / 0.05 g = 120
Hope this helps!
Let's write the reaction first:
<span>2 Au + 2 BrF</span>₃<span> + 2 KF → 2 KAuF</span>₄<span> + Br</span>₂<span>
</span>
To know which of the substances is the oxidizing agent, calculate the oxidation numbers of each element before and after the reaction. If the element's oxidation number decreases, then that is the oxidation agent. Let's calculate Br.
BrF₃: x + 3(-1) = 0; x = +3
Br₂: 0 (for any elemental form, oxidation number is 0)
The oxidation number is reduced from +3 to 0. <em>Thus, BrF₃ is the oxidizing agent.</em>