What is the percent of N in

Write the oxidation and reduction half reactions;

luda_lava [24]

Answer:

a)

$Fe^{2+}$ ⇒ $Fe^{3+}+e^-$

$Br_2+2e^-$ ⇒ $2Br^-$

b)

$Mg$ ⇒ $Mg^{2+}+2e^-$

$Cr^{3+}+e^-$ ⇒ $Cr^{3+}$

Explanation:

A)

Remember that positive number superscripts mean electrons lack and negative numbers mean electrons 'excess' (if we compare it with the neutral element). So, for the case of Fe2+ which is converted to Fe3+, we know that in Fe2+ there is a two electrons lack, while in Fe3+ there is a 3 electrons lack; it means that Fe2+ was converted to Fe3+ but releasing one electron:

$Fe^{2+}$ ⇒ $Fe^{3+}+e^-$

The same analysis is applied to Br2; Br2 is a molecule which is said to have a zero superscript because it is an apolar covalent bond; and it is converted to Br-, which, according to what I wrote above, means that there is a one electron excess. So, Br2 must have received an electron in order to change to Br-; but Br2 can't change to Br- as simple as that because Br2 is a molecule, not an atom; it is a molecule that has two Br atoms, so, Br2 must give two Br- ions as products, but receiving one electron for each one:

$Br_2+2e^-$ ⇒ $2Br^-$

b)

Applying the same, in Mg2+ there is a 2 electrons lack, and in Mg is not electron lack (its superscript is zero), so Mg must have released two electrons in order to change to Mg2+:

$Mg$ ⇒ $Mg^{2+}+2e^-$

Cr3+ has a 3 electrons lack, and Cr2+ a two electrons one, so, Cr3+ must receive an electron to convert to Cr2+:

$Cr^{3+}+e^-$ ⇒ $Cr^{3+}$

3 0

4 years ago

Read 2 more answers

How do we know that K2CrO4 and Ba(NO3)2 are not solids?

navik [9.2K]

I would say is because of the Boron from O?

7 0

3 years ago

Part A of the lab involved adding 4 mL increments of distilled water to 5.00 mL of antimony trichloride solution. The antimony t

Mrrafil [7]

Answer:

0.0238M SbCl3, 1.07M H+, 1.14M Cl-

Explanation:

The total volume of the solution is:

4mL + 5.00mL + 12.0mL = 21mL

As the volume of the SbCl3 is 5.00mL, the dilution factor is:

21mL / 5.00mL = 4.2 times

The concentration of SbCl3 is:

0.10M SbCl3 / 4.2 times = 0.0238M SbCl3

The concentration of H+ = [HCl]:

4.5M / 4.2 times = 1.07M H+

The initial concentration of Cl- is:

3 times SbCl3 + HCl = 0.10M*3 + 4.5M =

<em>3 times SbCl3 because 1 mole of SbCl3 contains 3 moles of Cl-</em>

4.8M Cl- / 4.2 times = 1.14M Cl-

3 0

3 years ago

What are the 4 kingdoms listed in the Eukarya Domain? List all 4 Kingdoms

stellarik [79]

Answer:

protista, fungi, plant, animal

Explanation:

this is the answer

4 0

3 years ago

348 g of water starting at 4.0°Celsius is heated until his temperature is 37°Celsius. Calculate the amount of heat energy needed

attashe74 [19]

Answer:

48.049 kJ or 48049 J

Explanation:

Hello again.

So we know the formula $q = mc\Delta t$ . c is the heat capacity but this time, it is not given. However, water has a very well known heat capacity which is 4.184 J/(g°C). This is in fact the number we refer to a calorie which is the amount of energy you burn that can raise the temperature of 1g of water by 1°C. So, plugging in values, you get the above. But double check if I am wrong.

7 0

3 years ago