Question

An unknown metal is suspected to be gold. When 2.8 j of heat are added to 5.6 g of the metal, its temperature rises by 3.9 ∘c.

Answer 1

Answer:- Heat capacity of the unknown metal is $c=0.128\frac{j}{g.^0C}$ and it's gold.

Solution:- To prove if the suspected metal is gold or not, we calculate it's heat capacity from given data and match it with the heat capacity table of metals. If calculated heat capacity match with the value given in table then the metal is gold else it is not.

For the calculations, we use the formula:

$q=mc\Delta T$

where, q is the heat energy, m is the mass, c is heat capacity and delta T is the change in temperature.

Since, we want to calculate the heat capacity, let's rearrange the formula for it:

$c=\frac{q}{m\Delta T}$

Let's plug in the given values:

$c=\frac{2.8j}{5.6g*3.9 ^0C}$

$c=0.128\frac{j}{g.^0C}$

This calculated value of unknown meal is same as the heat capacity of gold. So, the unknown metal is gold yes for sure.