Chem hw help please

[Superflyjsc]

Advertisement - Members don't see this ad

sorry for posting this up here but i didnt know where else i could post it. I figure its best if i post it here seeing that im pursing pharmacy.
Anyways, these are simple gen chem hw problems that i got stuck on.
i need help wit these 2 questions.. please help

(1) Volume of mixture was 5.25mL when following 2 solutions were mixed:
solution 1: 2.50 mL (density 1 = 0.80 g/mL)
solution 2: 2.75 mL (density 2 = 1.45 g/mL)

What is the density of the mixture?

(2) An ice cube of volume 30.0 mL and density 1.000 g/cm^3 floats in a liquid of density 1.59g/cm^3. What volume of the cube is submerged in the liquid?

Can u please explain as well as show how u came wit the answer? thanks

 

[gdk420]

Problem 1

Find the mass of the two solution. Add those together that would give u the total mass. Then find the density using the total mass and the total volume.

Solution 1: Denisty = mass / volume
.80= M1/2.50
M1 = 2

Solution 2: Density= mass/volume
1.45= M2/2.75
M2= 3.9875

Final solution: Density = (M1+M2)/ volume
=5.9875/5.25
= 1.14



Problem 2: since the density of the cube is less than the density of the liquid, it displaces its own weight in volume. A floating solid displaces a volume equal to its own weight. if the cube was more dense than the liquid it would only displace its own VOLUME, not its weight.

30 g of fluid / 1.59 = 18.9 cm^3

 

[dstormz]

Yes, to my knowledge, gdk's solutions are correct. 🙂

By the way, is this Inorganic Chemistry I?

Good luck, SuperFlyjsc.

 

[raindrop]

Isn't it funny how you'll never, ever need to know this when working in a retail pharmacy?

Well, not funny, actually pretty sad 🙁

sorry for posting this up here but i didnt know where else i could post it. I figure its best if i post it here seeing that im pursing pharmacy.
Anyways, these are simple gen chem hw problems that i got stuck on.
i need help wit these 2 questions.. please help

(1) Volume of mixture was 5.25mL when following 2 solutions were mixed:
solution 1: 2.50 mL (density 1 = 0.80 g/mL)
solution 2: 2.75 mL (density 2 = 1.45 g/mL)

What is the density of the mixture?

(2) An ice cube of volume 30.0 mL and density 1.000 g/cm^3 floats in a liquid of density 1.59g/cm^3. What volume of the cube is submerged in the liquid?

Can u please explain as well as show how u came wit the answer? thanks

 

[Keberson]

hhahahaha!!!!

 

[gdk420]

No this is general chemistry. Inorganic would concentrate on chemical reactions, molecular orbital theory, and etc of metal and sometimes organometallic reactions.