Question

A system consists of 1 mg of ClF gas. A mass spectrometer separates the gas into the species Cl^35F and Cl^37F.

a) Determine the molecular weight of ClF.

b) Identify the isotopes present.

c) Calculate the molar mass of ClF.

d) Find the atomic number of Cl.

Answer 1

The molecular weight of ClF is 53.96 amu. The isotopes present in ClF are Cl-35 and Cl-37. The molar mass of ClF is 8.96 x 10^-23 g. The atomic number of Cl is 17.

Step-by-step explanation:

(a) The molecular weight of ClF can be determined by adding the atomic masses of chlorine and fluorine. Chlorine has two naturally occurring isotopes, Cl-35 and Cl-37, with respective isotopic masses of 34.97 amu and 36.97 amu. Fluorine has only one stable isotope, F-19, with an isotopic mass of 18.99 amu. Therefore, the molecular weight of ClF is (34.97 amu * 1 + 18.99 amu * 1) = 53.96 amu.

(b) The isotopes present in ClF are Cl-35 and Cl-37, with a ratio of approximately 3:1.

(c) The molar mass of ClF can be determined by dividing the molecular weight of ClF by Avogadro's number. Avogadro's number is approximately 6.022 x 10^23, which represents the number of entities (atoms, molecules) in one mole of a substance. Therefore, the molar mass of ClF is (53.96 amu / 6.022 x 10^23) = 8.96 x 10^-23 g.

(d) The atomic number of Cl is 17, which represents the number of protons in the nucleus of a chlorine atom.