Units and Measurement

[ShitIZhard]

Problem 1

The density of platinum is 21.45 g/cm3 at 20C. Calculate the mass of 75.00 cm3 of platinum at this temperature.

guys i realllly need some help. I dont understand this problem it tells you to find the mass but you dont have the volume. If you dont have the volume how can you find the mass cuz the formula is Mass=Volume*Density. It also gives you the temperature. I dont understand how to use it in order to solve the problem.

Problem 2

The density of magnesium is 1.738g/cm3 at 20C. What is the volume of 87.50g of this metal at this temperature?

Same problem... but this time it doesnt give you the mass.... so how am i supposed to calculate the volume if i only have the density.


Please dont give me the actual answer, instead please try to explain how to solve this problem.

Please Help Me.

Thanks in advance

[maddy]

1) You are given the density and the volume.  I'm assuming the cm3 means cm^3 which is cubic centimeters.  I got 1608g of platinum.

2) Given density and mass.  density = mass/volume.  Rearrange and solve for volume.  I get about 50cm^3

[ShitIZhard]

maddy you are the man. let me go try that out. and yes i am sorry cm3 is cm^3.

[ShitIZhard]

yes i got the same answers ! thank you very very very much !