Question

A student wants to determine the empirical formula for titanium sulfide (TixSy). To do so, she reacted titanium with excess sulfur in a crucible, and recorded the following data: Mass of Crucible: 11.120 g Mass of titanium used: 8.820 g Mass of Crucible and product: 31.700 g what is the empirical formula of titanium sulfide based on her experiment?

Answer 1

Answer:  The empirical formula is $TiS_2$

Explanation:

Mass of Titanium (Ti) = 8.820 g

Mass of  product = (mass of Crucible and product) - mass of crucible = 31.700 g - 11.120 g = 20.58 g

Mass of sulphur (S) = mass of product - mass of titanium = 20.58 g - 8.820 g = 11.76 g

Step 1 : convert given masses into moles

Moles of Ti =$\frac{\text{ given mass of Ti}}{\text{ molar mass of Ti}}= \frac{8.820g}{48g/mole}=0.1838moles$

Moles of S=$\frac{\text{ given mass of S}}{\text{ molar mass of S}}= \frac{11.76g}{32g/mole}=0.3675moles$

Step 2 : For the mole ratio, divide each value of moles by the smallest number of moles calculated.

For Ti =$\frac{0.1838}{0.1838}=1$

For S = $\frac{0.3675}{0.1838}=2$

Thus the ratio of Ti : S = 1: 2

Hence the empirical formula is $TiS_2$