Sodium will do an ionic bond with

How many electrons does the 2nd main energy level hold when it is full?

UNO [17]

Answer:

8 electrons

Each principal energy level can contain up to 2n2 electrons, where n is the number of the level. Thus, the first level can contain up to 2 electrons, 2(12) = 2; the second up to 8 electrons, 2(22) = 8; the third up to 18, 2(32) = 18; and so on.

Explanation:

5 0

3 years ago

How many grams of Al would be needed to displace all of the copper ions in 71.8 mL of 0.610 M CuSO4?

Galina-37 [17]

The amount of Al that would be needed will be 0.79 grams

<h3>Stoichiometric calculations</h3>

From the equation of the reaction below:

$2 Al + 3 CuSO_4 --- > Al_2(SO_4)_3 + 3 Cu$

The mole ratio of Al to $CuSO_4$ is 2:3.

Mole of 71.8 mL. 0.610 M $CuSO_4$ = 0.610 x 71.8/1000 = 0.0438 moles

Equivalent mole of Al = 2/3 x 0.0438 = 0.029 moles

Mass of o.o29 moles Al = 0.029 x 26.98 = 0.79 grams

More on stoichiometric calculations can be found here: brainly.com/question/27287858

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4 0

2 years ago

Name three intermolecular forces that stabilize the structure of DNA, and explain how they act. A. flat, N-containing bases stac

Temka [501]

Answer:

B. nitrogen bases form hydrogen bonds to their complementary bases

C. sugar-phosphate chains form ion-dipole and hydrogen bonds to the aqueous surroundings

J. sugar-phosphate chains stack above each other, allowing for interaction through dispersion forces

Explanation:

B) The hydrogen bonding between complementary base pairs is such that the most energetically stable DNA configuration is achieved when adenine pairs with thymine and guanine pairs with cytosine. Thus although the spatial requirements of B-DNA potentially allow four complementary base pairs to be formed (i.e., G-T, G-C, A-T, and A-C), only the G-C and A-T base pairs are normally found in DNA.

C) The basic structure of DNA can be divided into two portions: the external sugar-phosphate backbone, and the internal bases. The sugar-phosphate backbone, as its name implies, is the major structural component of the DNA molecule. The backbone is constructed from alternating ribose sugar and phosphate molecules which are highly polar. Because the backbone is polar, it is hydrophillic which means that it likes to be immersed in water.

J. The anionic phosphate groups interact electrostatically with each other, and through ion-pi interactions with the aromatic ring sugars and nucleobases. When a guanidinium cation is present, the anionic phosphate group has been reduced to a dipole, and the tuning of denticity tunes the dipole magnitude and orientation. The electrostatic ion-ion interactions of the phosphate groups are reduced to ion-dipole interactions, and the interactions with the aromatic sugars and nucleobases are likewise modified to have a larger contribution from non-electrostatic London dispersion forces

8 0

3 years ago

Now molecules: Choose... molecules of H 2 + Choose... molecules of O 2 → Choose... molecules of H 2 O

kirill [66]

Consider this balanced chemical equation:
2 H2 + O2 → 2 H2O
We interpret this as “two molecules of hydrogen react with one molecule of oxygen to make two molecules of water.” The chemical equation is balanced as long as the coefficients are in the ratio 2:1:2. For instance, this chemical equation is also balanced:
100 H2 + 50 O2 → 100 H2O
This equation is not conventional—because convention says that we use the lowest ratio of coefficients—but it is balanced. So is this chemical equation:
5,000 H2 + 2,500 O2 → 5,000 H2O
Again, this is not conventional, but it is still balanced. Suppose we use a much larger number:
12.044 × 1023 H2 + 6.022 × 1023 O2 → 12.044 × 1023 H2O
These coefficients are also in the ratio of 2:1:2. But these numbers are related to the number of things in a mole: the first and last numbers are two times Avogadro’s number, while the second number is Avogadro’s number. That means that the first and last numbers represent 2 mol, while the middle number is just 1 mol. Well, why not just use the number of moles in balancing the chemical equation?
2 H2 + O2 → 2 H2O

6 0

3 years ago

A sample weighing 3.109 g is a mixture of Fe2O3 (molar mass = 159.69 g/mol) and Al2O3 (molar mass = 101.96 g/mol). When heat and

damaskus [11]

<u>Answer:</u> The mass fraction of $Fe_2O_3$ in the original sample is 0.637

<u>Explanation:</u>

We are given:

Mass of sample = 3.109 g

Mass of solid residue (Aluminium oxide + iron) = 2.515 g

Amount of mass lost = (3.109 - 2.515) = 0.594 g

The amount of mass lost from the sample is equal to the mass of oxygen lost from iron (III) oxide.

The chemical equation for the reaction of iron (III) oxide with hydrogen follows:

$Fe_2O_3+3H_2\rightarrow 2Fe+3H_2O$

In 1 mole of iron (III) oxide, 2 moles of iron are present and 3 moles of oxygen are present.

Mass of oxygen lost from 1 mole of iron (III) oxide = (3 × 16) = 48 g

Calculating the mass of iron (III) oxide by using unitary method:

48 grams of oxygen is lost when 159.69 grams of iron (III) oxide is reacted with hydrogen gas

So, 0.594 grams of oxygen will be lost when = $\frac{159.69}{48}\times 0.594=1.98g$ of iron (III) oxide is reacted with hydrogen gas

To calculate the mass fraction of iron (III) oxide, we use the equation:

$\text{Mass fraction of iron (III) oxide}=\frac{\text{Mass of iron (III) oxide}}{\text{Mass of sample}}$

Mass of iron (III) oxide = 1.98 grams

Mass of sample = 3.109 grams

Putting values in above equation, we get:

$\text{Mass fraction of iron (III) oxide}=\frac{1.98g}{3.109g}=0.637$

Hence, the mass fraction of $Fe_2O_3$ in the original sample is 0.637

4 0

4 years ago