Asample of metal has a mass of 5.2g and abosrbs 20.0 j of energy as it is heated from 30.0°c to 40.0°c. what is the identity of the metal?

a sample of metal has a mass of 5.2g and abosrbs 20.0 J of energy as it is heated from 30.0°C to 40.0°c. what is the identity of the metal?

Explanation:

1. for the first question, we must find the mass of the anhydrous salt, mgso₄. the molar mass for mgso₄·7h₂o is 246.47 g/mol, while that of mgso₄ is 120.37 g/mol.7.834 g mgso₄·7h₂o * 1 mol mgso₄·7h₂o/246.47 g * 1 mol mgso₄/1 mol mgso₄·7h₂o * 20.37 g mgso₄/mol = 0.647 g mgso₄

2. mass of water = mass of sample - mass of anhydrous salemass of water = 7.834 - 0.647 = 7.19 gpercent water in hydrate = 7.19/7.834 * 100 = 91.74%