Question

A 2.60 g sample of titanium metal reacts with 7.71 g of chlorine gas to form a compound.

a) Determine the empirical formula of the titanium chloride salt
b) Calculate the percent by mass of titanium and chloride in the salt

Answer 1

The reaction:

Ti(s) + Cl2(g) --> X compound

calculate mol of each

MW of Ti = 47.867 g/mol

mol of Ti = mass/MW = 2.6/47.867 =0.054317 mol of Ti

MW of Cl2 = 70.9060 g/mol

mol of Cl2 = mass/MW = 7.71/70.9060 = 0.1087 mol of Cl2

Relate:

Ti:Cl2 = 0.054317 :0.1087 --> 0.054317 /0.1087 = 1:2

so...

1 Ti per 2 Cl2 ... that is 1 Ti : 4 Cl

the molecule must be

TiCl4 --> Titanium tetrachloride

b)

% of Titanium and Chloride...

% titanium = mass of Ti / total mass = 2.6/(2.6+7.71) *100 = 25.218 % is Titanium

therefore,

%Cl2= 100% - Ti% = 100-25.218 = 74.782 %