All categories

3 years ago

Which of the following is not a physical change?

1 answer:

6 0

When you burn paper you are chemically altering it so that is the correct answer. When you do all the other choices all of the components stay the same. Just because it changes shapes doesn't mean it'll change chemically toom

You might be interested in

Burning wood in a fireplace is an example of what kind of energy conversion

Lunna [17]

Answer:

Potential energy

Explanation:

6 0

3 years ago

Read 2 more answers

When dissolved in water, a neutral molecule of calcium chloride dissociates into three ions - one calcium ion and two chloride i

Mashcka [7]

Explanation:

Calcium chloride is an ionic compound as it is formed by transfer of an electron to each chlorine atom.

So, being an ionic compound calcium chloride is able to dissociate completely into water.

Hence, the dissociation reaction will be as follows.

$CaCl_{2}(s) \rightarrow Ca^{2+}(aq) + 2Cl^{-}(aq)$

Since, two electrons has been lost by single calcium atom. Therefore, calcium atom will have a charge of +2.

Thus, we can conclude that the charge on the calcium ion, in elementary units is +2.

8 0

3 years ago

Why does changing the volume of a container change the pressure of the gas in it?

klio [65]

Changing the volume increases the area that the molecules collide with so the force is spread over a larger area.

6 0

3 years ago

Read 2 more answers

My professor gave me two questions to solve using the Van Der Waals Equation. She told us to solve for P and the second one we h

Fed [463]

Answer:

P=atm

$b=\frac{L}{mol}$

Explanation:

The problem give you the Van Der Waals equation:

$(P+\frac{n^{2}a}{V^{2}})(V-nb)=nRT$

First we are going to solve for P:

$(P+\frac{n^{2}a}{V^{2}})=\frac{nRT}{(V-nb)}$

$P=\frac{nRT}{(V-nb)}-\frac{n^{2}a}{v^{2}}$

Then you should know all the units of each term of the equation, that is:

$P=atm$

$n=mol$

$R=\frac{L.atm}{mol.K}$

$a=atm\frac{L^{2}}{mol^{2}}$

$b=\frac{L}{mol}$

$T=K$

$V=L$

where atm=atmosphere, L=litters, K=kelvin

Now, you should replace the units in the equation for each value:

$P=\frac{(mol)(\frac{L.atm}{mol.K})(K)}{L-(mol)(\frac{L}{mol})}-\frac{(mol^{2})(\frac{atm.L^{2}}{mol^{2}})}{L^{2}}$

Then you should multiply and eliminate the same units which they are dividing each other (Please see the photo below), so you have:

$P=\frac{L.atm}{L-L}-atm$

Then operate the fraction subtraction:

P= $P=\frac{L.atm-L.atm}{L}$

$P=\frac{L.atm}{L}$

And finally you can find the answer:

P=atm

Now solving for b:

$(P+\frac{n^{2}a}{V^{2}})(V-nb)=nRT$

$(V-nb)=\frac{nRT}{(P+\frac{n^{2}a}{V^{2}})}$

$nb=V-\frac{nRT}{(P+\frac{n^{2}a}{V^{2}})}$

$b=\frac{V-\frac{nRT}{(P+\frac{n^{2}a}{V^{2}})}}{n}$

Replacing units:

$b=\frac{L-\frac{(mol).(\frac{L.atm}{mol.K}).K}{(atm+\frac{mol^{2}.\frac{atm.L^{2}}{mol^{2}}}{L^{2}})}}{mol}$

Multiplying and dividing units,(please see the second photo below), we have:

$b=\frac{L-\frac{L.atm}{atm}}{mol}$

$b=\frac{L-L}{mol}$

$b=\frac{L}{mol}$

7 0

3 years ago

Is Bromothymol Blue acidic or basic?

notka56 [123]

It is mostly used in applications that need measuring substances that would have a relatively neutral pH . A common use is for measuring the presence of carbonic acid in a liquid. so yes its acidic

8 0

3 years ago