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2 years ago

The atom in a sample of an element must contain nuclei with the same number of?

1 answer:

7 0

Hey there!

Answer: Protons

The atom in a sample of an element must contain nuclei with the same number of protons. If the protons change in number, then the element will modify as well.

Thank you!

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Which of the following describes how air resistance affects the motion of a falling object?(1 point) Air resistance may change t

inessss [21]

Answer:

Air resistance opposes the gravity in a falling object hence the object loses speed once it reaches terminal velocity.

According to the experim

6 0

1 year ago

What is the theoretical yield of aspirin ( C 9 H 8 O 4 ), which has a molar mass of 180.15 g/mol, possible when reacting 3.03 g

pantera1 [17]

Answer:

The theoretical yield of aspirin is 3.95 grams

Explanation:

Step 1: Data given

Mass of salicylic acid = 3.03 grams

Volume of acetic anhydride = 3.61 mL

Density of acetic anhydride = 1.08 g/cm³

Step 2: The balanced equation

C4H6O3+C7H6O3→C9H8O4+C2H4O2

Step 3: Calculate moles salicylic acid

Moles salicylic acid = mass salicylic acid / molar mass salicylic acid

Moles salicylic acid = 3.03 grams /138.121 g/mol

Moles salicylic acid = 0.0219 moles

Step 4: Calculate mass acetic anhydride

Mass acetic anhydride = volume * density

Mass acetic anhydride = 3.61 mL * 1.08 g/mL

Mass acetic anhydride = 3.90 grams

Step 5: Calculate moles acetic anhydride

Moles acetic anhydride = 3.90 grams / 102.09 g/mol

Moles acetic anhydride = 0.0382 moles

Step 6: Calculate limiting reactant

For 1 mol salicylic acid we need 1 mol acetic anhydride to produce 1 mol aspirin

Salicylic acid is the limiting reactant. It will completely be consumed. (0.0219 moles). Acetic anhydride is in excess. There will react 0.0219 moles. There remain 0.0382 - 0.0219 =0.0163 moles

Step 7: Calculate moles aspirin

For 1 mol salicylic acid we need 1 mol acetic anhydride to produce 1 mol aspirin

For 0.0219 moles salicylic acid we'll have 0.0219 moles aspirin

Step 8: Calculate theoretical yield of aspirin

Mass of aspirin = moles aspirin *molar mass aspirin

Mass of aspirin = 0.0219 moles *180.15 g/mol

Mass of aspirin = 3.95 grams

The theoretical yield of aspirin is 3.95 grams

7 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).

#pa follow and heart po para sa iba pang answer at pa brainlest answer na den

7 0

3 years ago

What three mechanisms regulate the heart

Kazeer [188]

The SA node, the cardiac center in the medulla oblongata, and the endocrine system

5 0

2 years ago

The teacher said the volume of the liquid was 500 mL when measured a student found it was 499.7 mL what is the students percent

Natalka [10]

Answer:

Explanation:

The percentage error of a certain measurement can be found by using the formula

$P(\%) = \frac{error}{actual \: \: number} \times 100\% \\$

From the question

error = 500 - 499.7 = 0.3

actual volume = 500 mL

We have

$p(\%) = \frac{0.3}{500} \times 100 \\ = \frac{3}{50} \\$

We have the final answer as

Hope this helps you

4 0

3 years ago