How is it possible for helium to have 8 spectral lines when it only has 2 electrons?

PLEASE HELP!!!!!!!

dsp73

Answer: 1. $2Al+3CuCl_2\rightarrow 2AlCl_3+3Cu$

2. 3 moles of $CuCl_2$ : 2 moles of $Al$

3. 0.33 moles of $CuCl_2$ : 0.92 moles of $Al$

4. $CuCl_2$ is the limiting reagent and $Al$ is the excess reagent.

5. Theoretical yield of $AlCl_3$ is 29.3 g

Explanation:

To calculate the moles :

$\text{Moles of solute}=\frac{\text{given mass}}{\text{Molar Mass}}$

$\text{Moles of} Al=\frac{25.0g}{27g/mol}=0.92moles$

$\text{Moles of} CuCl_2=\frac{45.0g}{134g/mol}=0.33moles$

The balanced chemical equation is:

$2Al+3CuCl_2\rightarrow 2AlCl_3+3Cu$

According to stoichiometry :

3 moles of $CuCl_2$ require = 2 moles of $Al$

Thus 0.33 moles of $CuCl_2$ will require= $\frac{2}{3}\times 0.33=0.22moles$ of $Al$

Thus $CuCl_2$ is the limiting reagent as it limits the formation of product and $Al$ is the excess reagent.

As 3 moles of $CuCl_2$ give = 2 moles of $AlCl_3$

Thus 0.33 moles of $CuCl_2$ give = $\frac{2}{3}\times 0.33=0.22moles$ of $AlCl_3$

Theoretical yield of $AlCl_3=moles\times {\text {Molar mass}}=0.22moles\times 133.34g/mol=29.3$

Thus 29.3 g of aluminium chloride is formed.

5 0

3 years ago

Van dar waals are the dominant molecular force in the sodium chloride.

Vedmedyk [2.9K]

Answer:

Recall the two conceptual steps necessary to dissolve a solute and form a solution

Key Points

There are two conceptual steps to form a solution, each corresponding to one of the two opposing forces that dictate solubility.

The first conceptual step is dissolution, which corresponds to the force of the solvent-solvent and solute-solute intermolecular attractions that needs to be broken down.

The second conceptual step is solvation, which corresponds to the force of the solute-solvent intermolecular attraction that needs to be formed in order to form a solution.

Many intermolecular forces can contribute to solvation, including hydrogen bonding, dipole-dipole forces, Van Der Waals forces, and ion-dipole interactions.

Term

intermolecular forcesattractive and repulsive forces between molecules

The strength of the intermolecular forces between solutes and solvents determines the solubility of a given solute in a given solvent. In order to form a solution, the solute must be surrounded, or solvated, by the solvent. Solutes successfully dissolve into solvents when solute-solvent bonds are stronger than either solute-solute bonds or solvent-solvent bonds.

Qualitatively, one can determine the solubility of a solute in a solvent by using the rule “like dissolves like”. In general, solutes whose polarity matches that of the solvent will generally be soluble. For example, table salt (NaCl) dissolves easily into water (H2O) because both molecules are polar.

Intermolecular Forces and Their Importance in Solution Formation

There are two conceptual steps to form a solution, each corresponding to one of the two opposing forces that dictate solubility. If the solute is a solid or liquid, it must first be dispersed — that is, its molecular units must be pulled apart. This requires energy, and so this step always works against solution formation (always endothermic, or requires that energy be put into the system).

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7 0

3 years ago

A fire is an example of ________________ reaction, because heat is _____________ the system.

Over [174]

d. exothermic; leaving

Exothermic reaction is a reaction that produces heat in the reaction whereas the endothermic reaction is a reaction in which heat is required to be given in the reaction to produce product.
Fire is an exothermic reaction.
A fire is produced due to oxidation of the fuel in the form of liquid or gas.
A fire is an example of combustion.
In fire both heat and light are left from fire due to the oxidation of fuel.

Hence, option d. exothermic; leaving is the correct option.

Learn more about fire:

brainly.com/question/12761984

8 0

3 years ago

Read 2 more answers

A rule of thumb in baking is that 1/2 teaspoon of baking soda is neutralized by one cup of sour milk. the acid component in sour

Sophie [7]

Answer : The ionic equation will be:

$CH_3CH(OH)COO^-(aq)+H^+(aq)+Na^+(aq)+HCO_3^-(aq)\rightarrow CH_3CH(OH)COO^-(aq)+Na^+(aq)+H_2O(l)+CO_2(g)$

Explanation :

Neutralization reaction : It is a type of chemical reaction in which an acid react with a base to give salt and water as a product that means it reacts to give a neutral solution.

When baking soda (sodium hydrogen carbonate) base react with lactic acid then it react to gives sodium lactate, carbon dioxide and water as a product.

The balanced chemical reaction will be:

$CH_3CH(OH)COOH(aq)+NaHCO_3(aq)\rightarrow CH_3CH(OH)COONa(aq)+H_2O(l)+CO_2(g)$

The ionic equation will be:

$CH_3CH(OH)COO^-(aq)+H^+(aq)+Na^+(aq)+HCO_3^-(aq)\rightarrow CH_3CH(OH)COO^-(aq)+Na^+(aq)+H_2O(l)+CO_2(g)$

3 0

3 years ago

Which element has the electron configuration 2-4?

denpristay [2]

Carbon has the electronic configuration 2,4

4 0

3 years ago