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3 years ago

Is anyone good at chemistry if so can someone help me please ? (NO LINKS)

Chemistry

1 answer:

Sati [7]3 years ago

4 0

So, what's shown here is the ion product of pure water: that is, the product of the concentrations of hydronium and hydroxide ions in pure water at 25 °C. By this relation, if you know the [H₃O⁺], you can calculate the [OH⁻], and vice-versa.

Since [H₃O⁺] × [OH⁻] = 1.0 × 10⁻¹⁴, [OH⁻] = (1.0 × 10⁻¹⁴)/[H₃O⁺].

Substituting the given [H₃O⁺] as 1.25 × 10⁻² M:

[OH⁻] = (1.0 × 10⁻¹⁴)/(1.25 × 10⁻² M) = 8.0 × 10⁻¹³ M.

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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

What is an example of kinetic energy at work,1 a ball lodge in the tree, 1 a frisbee flaying in the air, 3 a car in the garage

AfilCa [17]

Answer:

a frisbee flaying in the air

Explanation:

Kinetic energy can be defined as an energy possessed by an object or body due to its motion.

Mathematically, kinetic energy is given by the formula;

$K.E = \frac{1}{2}MV^{2}$

Where;

K.E represents kinetic energy measured in Joules.
M represents mass measured in kilograms.
V represents velocity measured in metres per seconds square.

Hence, an example of kinetic energy at work is a frisbee flaying in the air because it would possess energy due to its motion in the air.

8 0

3 years ago

What is the mass of an object that requires a force of 25 N to accelerate at 5 m/s/s?

AfilCa [17]

The mass is 6 Kilograms

Explanation:

Force
=
mass
⋅
acceleration

30
=
m
⋅
5

m
=
6
K
g
The mass is 6 Kilograms

8 0

3 years ago

Are all acids dangerous? Give at least two examples to show what you mean.

juin [17]

Answer:

Laboratory acids are far too dangerous to taste, but you will have swallowed some dilute weak acids. Acids have a sour taste, like vinegar, which contains ethanoic acid, and lemons, which contain citric acid. These are safe to use in food, but they can still hurt if they get into a cut or into your eyes.

Explanation:

They can safely be consumed and do not irritate the skin. However, at greater concentrations weak acids can be harmful. Acids can react violently with water and are harmful in the presence of moisture in the mouth or eyes or in proximity with other aqueous solutions.

hope that helps!

4 0

4 years ago

Imagine that you traveled to the Moon for a vacation and discovered that your weight is different there. How would your weight b

dmitriy555 [2]

Answer

No you did not lose weight.

Explanation:

Weight is the force acting on an object, Gravity is a force on earth which does not apply to the moon so your weight may change depending in where you are but your mass will stay the same because mass measures the matter of an object ITSELF! Have a nice day....

8 0

3 years ago