What is the difference between squares and circles

Potassium thiocyanate, KSCN, is often used to detect the presence of Fe3+ ions in solution through the formation of the red Fe(H

Natalija [7]

Answer:

Ferric ions left in the solution at equilibrium is $8.0\times 10^{-6} M$ .

Explanation:

Moles of ferric nitrate in 0.700 L = n

Volume of the solution = V = 0.700 L

Molarity of ferric nitrate = M = 0.00150 M

$n=M\times V=0.00150 M\times 0.700 L=0.00105 mol$

Moles of potassium thiocyanate in 0.700 L = n'

Volume of the potassium thiocyanate solution = V' = 0.700 L

Molarity of potassium thiocyanate = M' = 0.200 M

$n'=M'\times V'=0.200 M\times 0.700 L=0.140 mol$

Molarity of ferric ions after mixing :

1 mol of ferric nitrate gives 1 mol of ferric ions.Then 0.00105 mol ferric nitrate will :

Moles of ferric ions = 0.00105 mol

$M_1=\frac{0.00105 mol}{0.700 L+0.700 L}=0.00075 M$

Molarity of thiocyanate ions after mixing :

1 mol of potassium thiocyanate gives 1 mol of thiocyanate ions.Then 0.140 mol potassium thiocyanate will give:

Moles of thiocyanate ions = 0.140 mol

$M_2=\frac{0.140 mol}{0.700 L+0.700 L}=0.1 M$

Complex equation:

$Fe^{3+}+SCN^-\rightleftharpoons [Fe(SCN)]^{2+}$

0.00075 M 0.1 M 0

At equilibrium:

(0.00075 M -x) (0.1 M-x) x

The formation constant of the given complex = $K_f=8.9\times 10^2$

$K_f=\frac{[[Fe(SCN)]^{2+}]}{[[Fe^{3+}]][SCN^{-}]}$

$8.9\times 10^2=\frac{x}{(0.00075 M -x)\times (0.1 M-x)}$

Solving for x:

x = 0.000742 M

Ferric ions left in the solution at equilibrium :

= (0.00075 M -x) = (0.00075 M - 0.000742 M)= $8.0\times 10^{-6} M$

5 0

3 years ago

When the following equation is balanced, the coefficient of water is

Genrish500 [490]

Answer:

2

Explanation:

it make the correction

5 0

3 years ago

In 2005, a Nevada silver mine exported 200 tons of silver. In 2008, as the silver supply became exhausted, it only exported 25 t

lianna [129]

The rate of change in the amount of silver supplied is equal to the ratio of the difference in the amount supplied to the number of years elapsed from 2005 to 2008. That is,
rate of change = (25 - 200) / (2008 - 2005) = -173/3
The answer is letter A.

8 0

3 years ago

Read 2 more answers

What is the volume of as sample that has a mass of 40.0 g and a density of 4.30 g/mL?

kati45 [8]

Explanation:

density = mass/volume so volume = mass/density = 40/4.30

4 0

3 years ago

Why must there be two chlorine atoms for every one calcium atom

Nady [450]

Answer:

There must be two Chlorine atoms for every one Calcium atom in order to fulfill Chlorine's octet rule and pair Calcium's unpaired electrons.

Explanation:

Calcium has two unpaired electrons in its Lewis dot structure, while Chlorine has one unpaired electron.

So why can't we just make a double bond for one Chlorine?

Chlorine has seven valence electrons, so once it shares electrons with Calcium, the octet rule is accomplished, and no more pairs can be made.

4 0

4 years ago