Question

Platinum has a density of 21 g/cm3. a platinum ring is placed in a graduated cylinder that contains water. the water level rises from 5.0 ml to 5.3 ml when the ring is added. what is the mass of the ring?

Answer 1

Answer:

The mass of the ring is 6.3 kg.

Explanation:

It is given that,

Density of platinum, $d=21\ g/cm^3$

A platinum ring is placed in a graduated cylinder that contains water. the water level rises from 5.0 ml to 5.3 ml when the ring is added. the volume of the ring is, (5.3 - 5) mL = 0.3 mL

Volume of the ring, $V=0.3\ cm^3$

We need to find the mass of the ring. The density of any substance is given by :

$d=\dfrac{m}{V}$

$m=d\times V$

$m=21\ g/cm^3\times 0.3\ cm^3$

m = 6.3 kg

So, the mass of the ring is 6.3 kg. Hence, this is the required solution.

Answer 2

The little lump of platinum that you dropped into the graduated cylinder has

         (5.3 - 5.0) = 0.3 mL  =  0.3 cm³ of volume.

That's nothing but a metal shaving, a little sliver, maybe like
a 1/4-inch piece cut out of a metal paper-clip.  I'm surprised
that you can read the graduated cylinder that precisely.

Its mass is

           (0.3 cm³) x (21 gm/cm³)  =  6.3 grams  =  0.0063 kg .