Amolecule in which the central atom forms three single bonds and has one lone pair is said to have a shape.
a) planar
b) tetrahedral
c) pyramidal
d) bent linear

Answer : The correct option is, (c) pyramidal

Explanation :

As we are given that a molecule in which the central atom forms three single bonds and has one lone pair that means the central metal atom has 3 bond pairs and 1 lone pair of electrons.

There are total 4 electron pairs. So, the hybridization will be and the electronic geometry of the molecule will be tetrahedral.

But as there are three atoms or bonds around the central atom and the fourth position occupied by lone pair of electrons. The repulsion between lone and bond pair of electrons is more and hence the molecular geometry will be pyramidal.

Hence, correct option is, (c) pyramidal

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%