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3 years ago

Hi, Im new! But, why is physical and chemical changes are different?

Chemistry

1 answer:

MariettaO [177]3 years ago

3 0

Answer:

Physical and chemical changes are different because one deals with changes to ones shape or form, while chemical is changing one substance to another.

Explanation:

A example of a physical change would be cutting a block of wood into a cube of would, its physical change changes from a block to a cube. A chemical change is changing the substance into another substance so for example, burning that cube of wood in a fire. The fire is burning the wood into ash meaning it's no longer wood but ash.

Hope this helps.

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Why aerosol is called colloidal dispersion dosage form?

Gnom [1K]

Answer:

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4 years ago

Which diagram represents an electrically neutral atom?

Rom4ik [11]

Answer:

Explanation:

I hope this right, I'm sorry if it's not.

For an atom to be neutral, it has to have the same amount of protons and electrons. Because protons and electrons have opposite charges, when there is an equal amount of them they balance each other out

5 0

3 years ago

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A force that acts on rock to change its shape or volume is called

sineoko [7]

Answer:

The answer would be stress

Explanation:

A force that acts on rock to change its shape or volume is stress. Stress adds energy to the rock. The energy is stored in the rock until it changes shape or breaks. Three different kinds of stress can occur in the crust—tension, compression, and shearing.

I hope this helps

8 0

3 years ago

Aspirin can be prepared from salicylic acid ( C 7 H 6 O 3 CX7HX6OX3), which has a molar mass of 138.12 g/mol, and acetic anhydri

pychu [463]

Answer: The theoretical yield of aspirin is 4.14 g

Explanation:

To calculate the moles :

$\text{Moles of solute}=\frac{\text{given mass}}{\text{Molar Mass}}$ $\text{Moles of salicylic acid}=\frac{3.20g}{138.12g/mol}=0.023moles$

mass of acetic anhydride = $density\times volume =1.082g/ml\times 3.71ml=4.01g$

$\text{Moles of acetic anhydride}=\frac{4.01g}{102.04g/mol}=0.039moles$

$C_9H_6O_3+C_4H_6O_3\rightarrow C_9H_8O_4+C_2H_3O_2$

According to stoichiometry :

1 mole of salycylic acid require 1 mole of acetic anhydride

Thus 0.023 moles of salycylic acid require= $\frac{1}{1}\times 0.023=0.023moles$ of acetic anhydride

Thus salycylic acid is the limiting reagent as it limits the formation of product and acetic anhydride is the excess reagent.

As 1 mole of salycylic give = 1 mole of aspirin

Thus 0.023 moles of salycylic acid give = $\frac{1}{1}\times 0.023=0.023moles$ of aspirin

Mass of aspirin = $moles\times {\text {Molar mass}}=0.023moles\times 180.15g/mol=4.14g$

Thus theoretical yield of aspirin is 4.14 g

4 0

3 years ago

How can equilibrium of a closed system chemical reaction be disturbed? Select all that apply.

charle [14.2K]

The correct answers are :

Changing the volume of the system.

Changing the temperature of the system.

Equilibrium will remain unaffected if the concentration of products and reactants are kept the same, and the temperature of the system is kept constant.

As the system is closed, we cannot add or remove products or reactants.

Change in temperature will shift the chemical equilibrium towards the reactant or product depending on whether the reaction is exothermic or endothermic.

Also change in volume will shift the chemical equilibrium of a chemical reaction if the reactants or products or both are gases.

8 0

3 years ago

Read 2 more answers