Select the statement below that describes the magnetic environment of hydrogens bonded to the sp2 hybrid carbons of pi systems relative to alkyl hydrogens bonded to sp3 hybrid carbons:

A) Are deshielded and resonate downfield
B) Are shielded and resonate upfield
C) Are shielded and resonate downfield
D) Are deshielded and resonate upfield

Are deshielded and resonate downfield

Explanation:

When electron density in neighboring atoms or groups is reduced, then the environment is said to be deshielded. Deshielding is observed when an atom is attached to electronegative atom. Deshielding increase in increase in chemical shift and NMR peaks observed in down field.

sp2 hybrid carbon is more electronegative than sp3. Therefore hydrogen attached to sp2 is deshielded and resonate at downfield.

Therefore, among the given, option A is correct.

'Are deshielded and resonate downfield'

b

explanation:

mitosis

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%