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2 years ago

Define concentration and give examples.

Chemistry

1 answer:

Crank2 years ago

7 0

Answer:

Concentration: The amount of a given substance within a set solution.

Explanation:

For example, the units for concentration include mol/ $dm^{3}$ which means that if a substance has 3 mol/ $dm^{3}$ , it means 3 moles of that substance is in a 1 dm cubed of that solution. You could give examples of the concentration of acids like Hydrochloric Acid (HCl) and alkalis like Hydroxide (OH).

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Five students performed a Kjeldahl nitrogen analysis of a protein sample. The following weight % nitrogen values were determined

Sunny_sXe [5.5K]

Answer:

G_calculated = 1.756

The outlier should be rejected, as G_cal > G_tab (= 1.463) at 95 % confidence.

Explanation:

The Grubb's test is used for identifying an outlier in data, which is from the same population. For this, a statistical term, G, is calculated for the suspected outlier. If the calculated value is greater than the tabulated G value then the suspected value is rejected. This term is given as,

G_calculated = | suspect value - mean| / s

Here, suspect value is 13.8, mean is to be taken of all the data (including suspected value). s is the standard deviation of the sample data.

s is calculated from the following formula:

s = (Σ(xi - x)²/(N-1))^1/2

Here, x is the mean, which is 15.24, xi is individual value and N is the total number of data (5).

From the above formula, s is found to be

Standard Deviation, s = 0.820

Now for G value,

G_calculated = | 13.8 - 15.24| / (0.820)

G_ calculated = 1.756

The tabulated G value at 95 % confidence and N -1 (5 - 1 = 4) degree of freedom is, 1.463.

As calculated G (1.756) is greater than the tabulated G (1.463), the value 13.8 is considered an outlier at 95 % confidence.

3 0

3 years ago

PLEASE HELP ME I NEED HELP

Crazy boy [7]

Answer:

5 moles S x (36.02 g S/mole S) = 180.1 grams of S

Explanation:

The periodic table has mass units for every element that can be correlated with the number of atoms of that element. The relationship is known as Avogadro's Number. This number, 6.02x $10^{23}$ , is nicknamed the mole, which scientists found to be a lot more catchy, and easier to write than 6.02x $10^{23}$ . The mole is correlated to the atomic mass of that element. The atomic mass of sulfur, S, is 36.02 AMU, atomic mass units. But it can also be read as 36.02 grams/mole.

This means that 36.02 grams of S contains 1 mole (6.02x $10^{23}$ ) of S atoms.

This relationship holds for all the elements. Zinc, Zn, has an atomic mass of 65.38 AMU, so it has a "molar mass" of 65.38 grams/mole. ^5.38 grams of Zn contains 1 mole of Zn atoms.

And so on.

5.0 moles of Sulfur would therefore contain:

(5.0 moles S)*(36.02 grams/mole S) = 180.1 grams of S

Note how the units cancel to leaves just grams. The units are extremely helpful in mole calculations to insure the correct mathematical operation is done. To find the number of moles in 70 g of S, for example, we would write:

(70g S)/(36.02 grams S/mole S) = 1.94 moles of S. [Note how the units cancel to leave just moles]

4 0

2 years ago

4. Which metals will be able to reduce copper ions in solution?

topjm [15]

4. The metals that would be able to reduce copper ions in solution would be hydrogen(H), lead(Pb), tin(Sb), nickel(Ni), iron(Fe), zinc(Zn), aluminum(Al), Magnesium(Mg), sodium(Na), calcium(Ca), potassium(K), and lithium(Li).

5. If you had a house with both copper- and zinc-galvanized iron water pipes,zinc would be desirable because A metal that is easily oxidized would rust more readily.

3 0

3 years ago

What type of bacteria convert the

Ksju [112]

Answer: B

Nitrifying bacterium, plural Nitrifying Bacteria, any of a small group of aerobic bacteria (family Nitrobacteraceae) that use inorganic chemicals as an energy source.

3 0

3 years ago

How is the behavior of electrons in an ionic bond different from the behavior of electrons in a covalent bond?

Valentin [98]

Answer:

The correct answer is "Electrons are transferred in an ionic bond"

Explanation:

The covalent bond is the chemical bond between atoms where electrons are shared, forming a molecule. Covalent bonds are established between non-metallic elements, such as hydrogen H, oxygen O and chlorine Cl. These elements have many electrons in their outermost level (valence electrons) and have a tendency to gain electrons to acquire the stability of the electronic structure of noble gas. The shared electron pair is common to the two atoms and holds them together.

An ionic bond is produced between metallic and non-metallic atoms, where electrons are completely transferred from one atom to another. During this process, one atom loses electrons and another one gains them, forming ions. Usually, the metal gives up its electrons forming a cation to the nonmetal element, which forms an anion.

In conclusion, chemical bonds are made so that atoms can have their entire outer layer, and thus have a stable electronic configuration. In the ionic bond, when the metallic atom has only one electron in its outer layer and the non-metallic one needs an electron to complete its layer; The metallic atom seats its electron to the non-metallic one. In the same way, the electron is shared in the covalent bond in order to achieve equilibrium.

Then, the main differences between the two bonds are that the ionic bond occurs between two different atoms (metallic and non-metallic), while the covalent bond occurs between two equal atoms (non-metallic). And in the covalent bond there is an electron compartment, while in the ionic bond there is an electron transfer.

So, the correct answer is "Electrons are transferred in an ionic bond"

8 0

3 years ago

Read 2 more answers

Define concentration and give examples.​

Define concentration and give examples.