Pair of substance that have properties entirely different from the atoms that make it up are

Assuming the volumes are additive, what is the [Cl−] in a solution obtained by mixing 297 mL of 0.675 M KCl and 664 mL of 0.338

Elden [556K]

<u>Answer:</u> The concentration of chloride ions in the solution obtained is 0.674 M

<u>Explanation:</u>

To calculate the number of moles for given molarity, we use the equation:

$\text{Molarity of the solution}=\frac{\text{Moles of solute}\times 1000}{\text{Volume of solution (in mL)}}$ .....(1)

<u>For KCl:</u>

Molarity of KCl solution = 0.675 M

Volume of solution = 297 mL

Putting values in equation 1, we get:

$0.675=\frac{\text{Moles of KCl}\times 1000}{297}\\\\\text{Moles of KCl}=\frac{(0.675mol/L\times 297)}{1000}=0.200mol$

1 mole of KCl produces 1 mole of chloride ions and 1 mole of potassium ion

Moles of chloride ions in KCl = 0.200 moles

<u>For magnesium chloride:</u>

Molarity of magnesium chloride solution = 0.338 M

Volume of solution = 664 mL

Putting values in equation 1, we get:

$0.338=\frac{\text{Moles of }MgCl_2\times 1000}{664}\\\\\text{Moles of }MgCl_2=\frac{(0.338mol/L\times 664)}{1000}=0.224mol$

1 mole of magnesium chloride produces 2 moles of chloride ions and 1 mole of magnesium ion

Moles of chloride ions in magnesium chloride = $(2\times 0.224)=0.448mol$

Calculating the chloride ion concentration, we use equation 1:

Total moles of chloride ions in the solution = (0.200 + 0.448) moles = 0.648 moles

Total volume of the solution = (297 + 664) mL = 961 mL

Putting values in equation 1, we get:

$\text{Concentration of chloride ions}=\frac{0.648mol\times 1000}{961}\\\\\text{Concentration of chloride ions}=0.674M$

Hence, the concentration of chloride ions in the solution obtained is 0.674 M

5 0

3 years ago

Sample Response: The change in her position (from beginning to end), along with the direction, is considered her displacement. T

kykrilka [37]

The sample response given in the question is right.

To find the answer, we need to know more about the distance and displacement.

<h3>How distance differ from displacement?</h3>

Displacement is the shortest distance between the initial and final points of a body.
It is the change in position with a fixed direction.
Displacement is a vector quantity and can be positive, negative or zero values.
Distance is the length of actual path of the body between initial and final positions.
It's a scalar quantity and it can be positive or zero.
The magnitude of displacement is less than or equal to the distance travelled.

Thus, we can conclude that the given sample response is right.

Learn more about distance here:

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3 0

2 years ago

What is the Ka of a weak acid (HA) if the initial concentration of weak acid is 4.5 x 10-4 M and the pH is 6.87? (pick one)

rewona [7]

Answer:

Ka = $4.04 \times 10^{-11}$

Explanation:

Initial concentration of weak acid = $4.5 \times 10^{-4}\ M$

pH = 6.87

$pH = -log[H^+]$

$[H^+]=10^{-pH}$

$[H^+]=10^{-6.87}=1.35 \times 10^{-7}\ M$

HA dissociated as:

$HA \leftrightharpoons H^+ + A^{-}$

(0.00045 - x) x x

[HA] at equilibrium = (0.00045 - x) M

x = $1.35 \times 10^{-7}\ M$

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

$Ka = \frac{(1.35 \times 10^{-7})^2}{0.00045 - 0.000000135}$

0.000000135 <<< 0.00045

$Therefore, Ka = \frac{(1.35 \times 10^{-7})^2}{0.00045 } = 4.04 \times 10^{-11}$

5 0

3 years ago

the grade of coal increases with (remember a higher grade of coal means it produces more energy when burned) quizlet

Aleks04 [339]

The grade of coal increases with compaction.

<h3>What is Compaction?</h3>

When something is crushed or compressed, it becomes compacted. After being collected, trash is often compressed to make it smaller and take up less room. Compaction is the process of making anything more compact, dense, or firmly packed.

grade of coal - The highest grade of coal is anthracite. It is a black, glossy, hard, brittle coal that is frequently referred to as hard coal. It has a high proportion of fixed carbon and a low proportion of volatile matter. Between subbituminous and anthracite, bituminous coal is the intermediate rank of coal.

to learn more about compaction go to -

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5 0

1 year ago

What is the trend in electronegativity as elements are considered from left to right in the periodic table?

Readme [11.4K]

Answer:

the answer is

the electronegativity of the elements from L to R increases

8 0

3 years ago