Acompound is found to contain 15.94 % boron and 84.06 % fluorine by mass. to answer the question, enter the elements in the order presented above. question 1: the empirical formula for this compound is . question 2: the molar mass for this compound is 67.81 g/mol. the molecular formula for this compound is .

given:

% B = 15.94 % by mass

% F = 84.06 % by mass

This means that for 100 g of the compound:

Mass of B = 15.94 g

Mass of F = 84.06 g

Now, atomic mass of B = 10.811 g/mol

Atomic mass of F = 18.998 g/mol

# moles of B = Mass of B/Atomic mass of B = 15.94 g/10.811 gmole-1 = 1.474 moles

# moles of F = Mass of F/ Atomic mass of F = 84.06/18.998 = 4.425 moles

The molar ratio of B and F in the given compound would be:

B = 1.474/1.474 = 1

F = 4.425/1.474 = 3

Therefore, the empirical formula is BF3

The corresponding empirical formula mass = 1* 10.811 + 3*18.998 = 67.805 g/mol i.e, 67.81 g/mol

It is given that the molar mass of the compound is 67.81 g/mol

The ratio of the two masses is:

n = empirical mass/molar mass = 67.81/67.81 = 1

Molecular formula = n*Empirical formula = 1*(BF3) = BF3

Hence, the molecular formula of the compound is BF3

a rain shadow is a dry region of land on the side that is protected against the prevailing winds of a mountain range. the prevailing winds are the winds that occur most of the time in a particular place of the earth

prevailing winds carry air toward the mountain range. as the air rises up over a mountain range, the air cools, water vapor condenses, and clouds form. on this side of the mountains, called the windward side, precipitation falls in the form of  rain  or snow. this dry air produces a  rain shadow.