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2 years ago

Help pleaseeee. over dilutions in chemistry

Chemistry

1 answer:

atroni [7]2 years ago

5 0

Answer:

5 L

Explanation:

We'll begin by calculating the molarity of the CaCl₂ solution. This can be obtained as follow:

Mole of CaCl₂ = 0.5 mole

Volume = 2 L

Molarity =?

Molarity = mole /Volume

Molarity = 0.5 / 2

Molarity = 0.25 M

Finally, we shall determine the volume of the diluted solution. This can be obtained as follow:

Molarity of stock solution (M₁) = 0.25 M

Volume of stock solution (V₁) = 2 L

Molarity of diluted solution (M₂) = 0.1 M

Volume of diluted solution (V₂) =?

M₁V₁ = M₂V₂

0.25 × 2 = 0.1 × V₂

0.5 = 0.1 × V₂

Divide both side by 0.1

V₂ = 0.5 / 0.1

V₂ = 5 L

Thus the volume of the diluted solution is 5 L

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Two colorless solutions are mixed together bubbles form as the solution is stirred give to possible explanations for this result

Aleks [24]

One possible answer could be that a chemical reaction has occurred.

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3 years ago

Thallium-207 decays exponentially with a half life of 4.5 minutes. if the initial amount of the isotope was 28 grams, how many g

Agata [3.3K]

An exponential decay law has the general form: A = Ao * e ^ (-kt) =>

A/Ao = e^(-kt)

Half-life time => A/Ao = 1/2, and t = 4.5 min

=> 1/2 = e^(-k*4.5) => ln(2) = 4.5k => k = ln(2) / 4.5 ≈ 0.154

Now replace the value of k, Ao = 28g and t = 7 min to find how many grams of Thalium-207 will remain:

A = Ao e ^ (-kt) = 28 g * e ^( -0.154 * 7) = 9.5 g

Answer 9.5 g.

7 0

3 years ago

"acid is responsible for the odor in rancid butter. a solution of 0.25 m butyric acid has a ph of 2.71. what is the ka for"

Salsk061 [2.6K]

Answer:- The Ka for the acid is $1.53*10^-^5$ .

Solution:- In general, monoprotic acid could be represented by HA. The dissociation equation for the ionization of HA is written as:

HA(aq)\rightarrow H^+(aq) + A^-(aq)

Now, we make the ice table for this equation as:

HA(aq)\rightarrow H^+(aq) + A^-(aq)

I 0.25 0 0

C -X +X +X

E (0.25 - X) X X

where, I stands for initial concentration, C stands for change in concentration and E stands for equilibrium concentration.

X is the change in concentration and from ice table it's same as the concentration of hydrogen ion that is calculated from given pH.

$Ka = [H^+][A^-]\frac{1}{HA}$

Where, Ka is the acid ionization constant. Let's plug in the values.

$Ka = \frac{X^2}{0.25-X}$

Let's calculate the value of X first using the equation:

$pH = -log[H^+]$ [/tex]

on taking antilog ob above equation we get:

$[H^+]=10^-^p^H$

$[H^+]=10^-^2^.^7^1$

$[H^+]$ = 0.00195

So, X = 0.001195

Let's plug in this value of X in the equation:-

$Ka=\frac{(0.00195)^2}{0.25-0.00195}$

$Ka=1.53*10^-^5$

So, the value of Ka for butyric acid is $1.53*10^-^5$ .

8 0

3 years ago

Read 2 more answers

PH3, explain why there is a partial positive on hydrogen and partial negative on phosphorus.

Paraphin [41]

Answer:

Phosphorus is more electronegative than hydrogen

Explanation:

Electronegativity is a measure of the tendency of an atom to attract a bonding pair of electrons towards itself thereby making a molecule to be polar. The Pauling scale is the most commonly used to measure electronegativity. Fluorine (the most electronegative element) is assigned a value of 4.0 on the Pauling's scale, and values range down to caesium and francium which are the least electronegative elements.

Electronegativity increases from left to right across the periodic table (across the period) hence, phosphorus is far more electronegative than hydrogen. Being more electronegative than hydrogen, phosphorus attracts the bonding electron pair of the P-H bond closer to itself than hydrogen. Since the electrons of the bond are closer to phosphorus than hydrogen, the phosphorus atom acquires a partial negative charge while the hydrogen atom acquires a partial positive charge.

3 0

3 years ago

Francine makes several measurements of the mass of a metal block. The data set is shown in the table below.

BARSIC [14]

Answer:

Mean

Explanation:

The mean of a series of measurements is calculated when a<em>ll the measurements are added up and then divided by the number of measurements taken</em>, as follows:

Sum of Measurements = 20.73 + 20.76 + 20.68 + 20.75 = 82.92

As<u> there are 4 measurements</u>, the mean is:

Mean = 82.92 / 4 = 20.73

3 0

3 years ago