Question

.You have just purchased a chain claimed to be pure gold. The chain weighs 60g and it displaces 4.0cm3 of water when fully immersed. Is it pure gold? ( s.g
of gold=19. 3)

Answer 1

Given:

The chain weighs 60g and it displaces 4.0cm³ of water when fully immersed.

To find:

If this gold is pure or not ?

Calculation:

First of all , try to remember ARCHIMEDES' PRINCIPLE :

• Since the chain displaces 4 cm³ of water upon being immersed completely, we can say that the volume of the chain is 4 cm³

• The above statement is as per the principle.

Now, the weight of the chain is 60 grams.

Let density of gold (as calculated practically) be $\rho$.

$\therefore \: \rho = \dfrac{mass}{volume}$

$\implies \: \rho = \dfrac{60 \: g}{4 \: {cm}^{3} }$

$\implies \: \rho = 15 \: g/ {cm}^{3}$

So, the calculated density of the chain is less than the actual density of gold ( 19.3 g/cm³).

Hence, the chain is not made up of pure gold.