# The Densities of Liquids and solids

O.k. so here is my problem. I will give you the whole problem just incase my mistake is somewhere else, but the volume for the metal and the density for the metal in the end seem to be wrong.

(Density of unknown liquid)

Mass of empty flask plus stopper 37.34g. Mass of stoppered flask plus water 63.67g. Mass of stoppered flask plus liquid 52.01. Mass of water (that I calculated) 26.33. Volume of flask(density of H2O at 25 degrees C, 0.9970 g/cm^3 (this was given) I calculated 37.45.

Mass of Liquuid 14.67. Density of liquid 14.72.

This is were my problem arises but I give you the above because the weight of the flask is the same...and I used that density.

(Density of unknwn metal)

Mass of stoppered flask plus metal 61.28. Mass of stoppered flask plus metal plus water 78.19. Mass of metal (according to my calculation) 23.94. Mass of water (also according to me) 16.91 and the volume of the water I calculated is 16.96. For the Volume of the metal I got 24.01 and for the density of the metal I got 0.991 g/cm^3....this seems odd, since the water and the metal would have the same density...so I figure I must be doing something wrong. I am really not sure what numbers to use to figure out the volume and density of the metal.

Please Help! I know this seems long, I just don't know were my mistake is.

## D=M/V

Just my calculations..

empty flask + stopper= 37.34g

flask + stopper + water= 63.67g

water= 63.67g - 37.34g= 26.33g

D of water = 0.9970g/cm^3

V of water = M/D

V water= 26.40cm^3

flask + stopper + liquid = 52.01g

liquid= 52.01g- 37.34g= 14.67g

V same as water so...26.40cm^3

then to get D for unknown liquid

D=M/V

D= 14.67g/26.40cm^3 = 0.5556g/cm^3

Unknown Metal D

(have to find the volume)

stoppered flask + metal = 61.28g

stoppered flask empty (from before)= 37.34g

metal mass = 61.28g- 37.34g = 23.94g

Stoppered flask + water= 78.19g

water mass = (78.19g + 23.94g)-37.34g= 67.79g

Vol of water = Mass/Density

67.79g/(0.9970g/cm^3)= 67.99cm^3

Orig Vol- new Vol= 67.99cm^3-26.40cm^3= 41.59 cm^3 (vol of metal)

D of metal= Mass/Vol

23.94g/41.59cm^3= _________g/cm^3?

Hint: it's not the same =D

## mass = volume x density

volume = mass/density

volume of flask = 26.33/0.9970 = 26.41 cc or therebouts, not 37.45.

I didn't go through the remainder except that the mass of liquid is correct at 14.67.

Repost if this doesn't clear it up for you.

**water mass = (78.19g + 23.94g)-37.34g= 67.79g **

**
Vol of water = Mass/Density
67.79g/(0.9970g/cm^3)= 67.99cm^3
**

I'm not sure I buy this part.

mass flask + metal + H2O = 78.19

mass flask + metal = 61.28

mass H2O = 78.19-61.28=16.91 g OR

flask + metal + H2O = 78.19

metal = 23.94

flask = 37.34

H2O = 78.19-23.94-37.34 = 16.91 g.

I think the mistake is ADDING the 23.94.

Check my thinking.

## Ya, I noticed that too...I reposted what I did clearer, so please look at that version. I wrote down everything I did and were my problem is.

Thanks for the help!

## Yes Now looking at that again...

it should be subtraction.

Thanks for catching that Dr.Bob =D

(I should check twice next time)

## The correction for this(If anybody cares to look anymore) (I feel I have a responsibility to correct the error

=()

So...

_______________________________________

water mass = 78.19g - 23.94g-37.34g=

16.91g

Vol of water = Mass/Density

16.91g/(0.9970g/cm^3)= 16.96cm^3

Orig Vol- new Vol= 26.40cm^3 -16.96cm^3= 9.44cm^3 (vol of metal)

D of metal= Mass/Vol

23.94g/9.44cm^3= 2.54g/cm^3?

I checked twice this time so it SHOULD be correct.

## To determine the volume and density of a liquid or solid, you typically use the formula:

Density = Mass / Volume

Let's analyze the given data and calculations step by step for the unknown liquid and the unknown metal.

For the unknown liquid:

1. Mass of empty flask plus stopper = 37.34 g

2. Mass of stoppered flask plus water = 63.67 g

3. Mass of stoppered flask plus liquid = 52.01 g

4. Mass of water = 26.33 g (calculated: 63.67 g - 37.34 g)

5. Volume of flask = 37.45 cm³ (calculated)

6. Mass of liquid = 14.67 g

7. Density of liquid = 14.72 g/cm³

Your calculations for steps 2-5 seem correct. However, there may be an error in your calculation for the volume of the flask (step 5), as the value you provided is slightly different from the given value of 37.45 cm³.

For the unknown metal:

1. Mass of stoppered flask plus metal = 61.28 g

2. Mass of stoppered flask plus metal plus water = 78.19 g

3. Mass of metal = 23.94 g (calculated: 78.19 g - 54.25 g)

4. Mass of water = 16.91 g (calculated: 78.19 g - 61.28 g)

The volume of the metal can be calculated by using the volume of water displaced when the metal is added to the flask:

5. Volume of water = 16.91 cm³ (calculated)

Now, to find the volume of the metal:

6. Volume of metal = Volume of water = 16.91 cm³

Finally, to calculate the density of the metal:

7. Density of metal = Mass of metal / Volume of metal

= 23.94 g / 16.91 cm³ = 1.42 g/cm³

It seems your calculation for the volume of the metal is incorrect (step 6). Make sure you are using the correct masses and volumes for the metal and water.

Also, note that the density of the metal should not necessarily be the same as that of water. Different metals have different densities, so it is possible for a metal to be less dense or more dense than water.