All categories

3 years ago

Which of the following does NOT involve a physical change?

Chemistry

1 answer:

jasenka [17]3 years ago

4 0

Answer:mixing decomposing

Explanation:

Melting and grinding changes the physical form and mixing decomposing doesn’t

You might be interested in

A/an _______ bond allows metals to conduct electricity

k0ka [10]

A bond allows metal to conduct electricity <span />

5 0

3 years ago

Read 2 more answers

Step 2: Now that you have counted the atoms on each side, add coefficients to balance the equation. Check your work by updating

Alja [10]

Answer:

The answers to your questions are given below.

Explanation:

__ NaBr + CaF₂ —> __ NaF + CaBr₂

The above equation can be balance as follow:

NaBr + CaF₂ —> NaF + CaBr₂

There are 2 atoms of F on the left side and 1 atom on the right side. It can be balance by writing 2 before NaF as shown below:

NaBr + CaF₂ —> 2NaF + CaBr₂

There are 2 atoms of Na on the right side and 1 atom on the left side. It can be balance by writing 2 before NaBr as shown below:

2NaBr + CaF₂ —> 2NaF + CaBr₂

Now, the equation is balanced.

Atom >>>> Reactant >>>> Product

Na >>>>>> 2 >>>>>>>>>>> 2

Br >>>>>>> 2 >>>>>>>>>>> 2

Ca >>>>>> 1 >>>>>>>>>>>> 1

F >>>>>>> 2 >>>>>>>>>>>> 2

5 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

Which of the changes gas to solid gas to liquid, liquid to solid liquid to gas,solid to liquid solid to gas will involve an outp

Verdich [7]

Answer:

Liquid to solid liquid to gas

Explanation:

Boiling a liquid result in a gas

7 0

2 years ago

5. Inside the mouth, these cells are joined together in a sheet. Why are they scattered here?

anyanavicka [17]

Answer:

Inside the mouth, these cells are joined together in a sheet. Why are they scattered here? They are scattered here because we disrupted there original form by scrapping them off our mouths and smearing them on the slide.

Explanation:

5 0

3 years ago