15. Water (H20) is made up of molecules with a bent structure, whereas hydrogen sulfide (H2S) is also made up of molecules with a bent structure. Why is the melting point of H2O much
higher than the melting point of H2S? Select all correct answers.
a. The intermolecular forces in H2S are much greater than those in H20
b. The intermolecular forces in H20 are much greater than those in H2S
c. The three-dimensional arrangement of water makes it a polar molecule
d. Hydrogen sulfide has a lower molar mass than water

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%

metals are good conductor of electricity. it has free electrons on their surface. according to electron pool theory, each atom present in a metal crystal losses all of its valence electron and as a result a pool of free is form. these pool of electrons are free to move and   conduct electricity easily   while making metal as good conductor.

the correct answer is a. the ability of electrons to flow throughout the metal.

if it's not useful, feel free to report for mistake in answer.