Question

1. use the data below to answer the questions.

mass of empty crucible: 19.95 g
mass of crucible + metal (before heating): 22.43 g
mass of crucible + metal oxide (after heating): 23.10 g
a. what is the mass of the metal?
b. what is the mass of the oxygen that has combined with the metal?
c. write the empirical formula for the metal oxide if the metal is tin.

Explanation:

Step1: Calculate the mass of the metal

The mass of the metal is the mass of the crucible + metal (before heating) minus the mass of the empty crucible.
$$22.43\space g - 19.95\space g=2.48\space g$$

Step2: Calculate the mass of oxygen

The mass of oxygen is the mass of the crucible + metal oxide (after heating) minus the mass of the crucible + metal (before heating).
$$23.10\space g - 22.43\space g = 0.67\space g$$

Step3: Calculate the moles of tin and oxygen

The molar mass of tin ($Sn$) is $118.71\space g/mol$, and the molar mass of oxygen ($O$) is $16.00\space g/mol$.
Moles of tin: $n_{Sn}=\frac{2.48\space g}{118.71\space g/mol}\approx0.0209\space mol$
Moles of oxygen: $n_{O}=\frac{0.67\space g}{16.00\space g/mol}\approx0.0419\space mol$

Step4: Find the ratio of tin to oxygen

Divide each mole value by the smaller mole value ($0.0209\space mol$)
Ratio of $Sn$: $\frac{0.0209\space mol}{0.0209\space mol} = 1$
Ratio of $O$: $\frac{0.0419\space mol}{0.0209\space mol}\approx2$

Answer:

a. The mass of the metal is $2.48\space g$.
b. The mass of the oxygen that has combined with the metal is $0.67\space g$.
c. The empirical formula for the metal oxide (if the metal is tin) is $SnO_{2}$.