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3 years ago

Calculate concentration of methylene blue . Give answer in molarity. concentration in ppm=4.8

Chemistry

1 answer:

PSYCHO15rus [73]3 years ago

8 0

Answer:

The molarity of methylene blue is 1.5 × 10⁻⁵ M

Explanation:

When we talk about aqueous solutions, 1 ppm means 1 mg of solute per liter of solution. We need to express this concentration in molarity, which is moles of solute per liter of solution. To convert mass to moles we need the molar mass of methylene blue(MB), which is 320 g/mol.

Then,

$\frac{4.8mgMB}{1Lsolution} .\frac{1gMB}{10^{3}mgMB } .\frac{1molMB}{320gMB} =1.5 \times 10^{-5} M$

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Rasheed calculates that his chemical reaction should produce 4 moles of product, but when he does the experiment, he gets only 3

Brut [27]

Answer:

The answer to your question is 75%

Explanation:

Data

Theoretical production = 4 moles

Experimental production = 3 moles

Percent yield = ?

Formula

$Percent yield = \frac{Experimental production}{Theoretical production} x 100$

Substitution

$Percent yield = \frac{3}{4} x 100$

Result

Percent yield = 75 %

8 0

3 years ago

Consider the following data for five hypothetical elements: Q, W, X, Y, and Z. Rank the elements from most reactive to least rea

aleksley [76]

Answer:

Y Q W Z X

Explanations:

The most reactive element is the element that will displace an element from it compound . The most reactive element will replace the less reactive element in it compound.

Q+ + Y Reaction occurs

Since the reaction occurs the element Y which is more reactive displaced element Q from it compound.

Q+W+ Reaction occurs

The reaction occurs, that means element Q replaces element w from it compound. Element Q is therefore more reactive than element W.

W+Z+ Reaction occurs

The reaction also occurs . This is an indication that element W replaces element Z in it compound. This means element W is very reactive than element Z.

X+Z+ No reaction

There is no reaction here. This is an indication that element X is less reactive than element Z. This is why element X can't displace element Y in it compound.

4 0

3 years ago

Identify the neutral element represented by this excited-state electron configuration, then write the ground-state electron conf

sineoko [7]

Answer:

1s² 2s² 2p³

Nitrogen

Explanation:

Excited state configuration: 1s² 2s² 2p² 3s¹

Unknown:

Ground state configuration = ?

Element symbol = ?

Solution:

Let us start by understanding what a ground state configuration entails:

A ground state configuration shows the lowest allowed energy levels of an atom. The excited state denotes when electrons have moved to higher energy levels away from their ground state.

The superscript in the configuration depicts the number of electrons in each of the sublevels.

We can use this number to identify the atom we are dealing with:

Total number of electrons = 2 + 2 + 2 + 1 = 7 electrons

The element with 7 electrons on the periodic table is Nitrogen.

Now, the ground state configuration:

In writing the electronic configuration of an atom, certain rules must be complied with.

Aufbau's principle states that the sublevels with lower energies are filled up before those with higher energies. The order of filling is:

1s 2s 2p 3s 3p 4s etc

To fill the s-orbital = 2 electrons

p-orbital = 6 electrons

The outermost shell electrons are usually the ones excited.

Now, the 3s¹ shell is an excited one taking 1 electron from the second energy level;

The ground state configuration is 1s² 2s² 2p³

5 0

3 years ago

Acid & Base Calculations Calculate the hydronium ion concentration for each. Tell whether it is an acid or a base. 1. pH = 5

Anuta_ua [19.1K]

Explanation:

pH is the negative logarithm of hydronium ion concentration present in a solution.

If the solution has high hydrogen ion concentration, then the pH will be low and the solution will be acidic. The pH range of acidic solution is 0 to 6.9
If the solution has low hydrogen ion concentration, then the pH will be high and the solution will be basic. The pH range of basic solution is 7.1 to 14
The solution having pH equal to 7 is termed as neutral solution.

To calculate the pH of the solution, we use equation:

$pH=-\log[H_3O^+]$ ......(1)

To calculate the pOH of the solution, we use the equation:

pH + pOH = 14 ........(2)

For 1:

We are given:

pH = 5.54

Putting values in equation 1, we get:

$5.54=-\log[H_3O^+]$

$[H_3O^+]=2.88\times 10^{-6}M$

Now, putting values in equation 2, we get:

14 = 5.54 + pOH

pOH = 8.46

The solution is acidic in nature.

For 2:

We are given:

pOH = 9.7

Putting values in equation 2, we get:

14 = 9.7 + pH

pH = 4.3

Now, putting values in equation 1, we get:

$4.3=-\log[H_3O^+]$

$[H_3O^+]=5.012\times 10^{-5}M$

The solution is acidic in nature.

For 3:

We are given:

pH = 7.0

Putting values in equation 1, we get:

$7.0=-\log[H_3O^+]$

$[H_3O^+]=1.00\times 10^{-7}M$

Now, putting values in equation 2, we get:

14 = 7.0 + pOH

pOH = 7.0

The solution is neither acidic nor basic in nature.

For 4:

We are given:

pH = 12.9

Putting values in equation 1, we get:

$12.9=-\log[H_3O^+]$

$[H_3O^+]=1.26\times 10^{-13}M$

Now, putting values in equation 2, we get:

14 = 12.9 + pOH

pOH = 1.1

The solution is basic in nature.

For 5:

We are given:

pOH = 1.2

Putting values in equation 2, we get:

14 = 1.2 + pH

pH = 12.8

Now, putting values in equation 1, we get:

$12.8=-\log[H_3O^+]$

$[H_3O^+]=1.58\times 10^{-13}M$

The solution is basic in nature.

For 6:

We are given:

$[H_3O^+]=1\times 10^{-5}M$

Putting values in equation 1, we get:

$pH=-\log(1\times 10^{-5})$

$pH=5$

Now, putting values in equation 2, we get:

14 = 5 + pOH

pOH = 9

The solution is acidic in nature.

5 0

3 years ago

Which of the following compounds most likely has the least bond energy?

Evgesh-ka [11]

Answer:

I2; I–I bond length = 266 pm

Explanation:

Bond length is inversely related to bond strength. The longer the bond length, the weaker the bond. The shorter the bond length the stronger the bond. A large bond distance implies that there is poor interaction between the atoms involved in the bond. A long bond distance or bond length may even indicate the absence of covalent interaction between the atoms involved.

4 0

3 years ago