What is the molecular formula of a compound if its empirical formula is cfbro and its molar mass is 381.01 g/mol?
a. cfbro
b. c2f2br2o2
c. c3f3br3o3
d. c2f3br2o3
e. c4f4br4o me

 C.

Explanation:

Molecular formula is the chemical formula which depicts the actual number of atoms of each element present in the compound.

Empirical formula is the simplest formula which depicts the whole number of atoms of each element present in the compound.

Given empirical formula:

Thus empirical mass= 12+19+80+16= 127 g

Given : Molar mass= 381.01 g

Now we have to calculate the molecular formula.

Thus Molecular formula is :

you need to take a look at the periodic system in order to sort these elements into pairs that would most likely exhibit similar chemical properties. first, you need to find elements that are found in the same group (groups are vertical in the periodic system), and then to see whether they have the same valence number. if they meet these criteria, they will have similar properties.

the first pair: ne (neon) and kr (krypton), are noble gases found in group 8

the second pair: li (lithium) and k (potassium), found in group 1

the third pair: s (sulfur) and te (tellurium), found in group 6

a gas, having a molecular weight of 13 kg/kmol and a kinematic viscosity of 0.25 cm2/s, flows through a pipe 0.25 m internal diameter and 5 km long at the rate of 0.4 m3/s and is delivered at atmospheric pressure.