A man receives a platinum ring from his fiancee. Before the wedding, he notices that the ring feels a little light for its size and decides to measure its density. He places the ring on a balance and finds that it has a mass of 3.15 grams. He then finds that the ring displaces 0.233 cm3 of water. Given that the density of pure platinum is 21.4 g/cm3, is this ring genuine

The ring is probably not geniune.

Explanation:

To solve this problem we first need to calculate the density of the ring:

The mass is given by the problem, and we're able to assess the volume by keeping in mind Archimede's principle (the volume of water displaced by an object is equal to the object's volume).

Given that the ring density is significantly lower than the density of pure platinum, the ring is probably not geniune.

your answer is a. the enthalpy of formation for a pure element in its standard state is always positive.