Question

A 0.500 g sample of a compound containing only antimony and oxygen was found to contain 0.418 g of antimony and 0.082 g of oxygen. What is the simplest formula for the compound?

Answer 1

The simplest formula for the compound made of antimony and oxygen is calculated by finding the mole ratio of the two elements. After determining the moles, the ratio is 1:1.5, and upon scaling to get whole numbers, the simplest formula is identified as Sb₂O₃

Step-by-step explanation:

To find the simplest formula for a compound containing antimony and oxygen, we should start by determining the moles of each element in the 0.500 g sample. The student has stated that the sample contains 0.418 g of antimony and 0.082 g of oxygen. Using the atomic masses from the periodic table (antimony: 121.76 g/mol, oxygen: 16.00 g/mol), we calculate the moles of each:

• Antimony moles = 0.418 g / 121.76 g/mol = 0.00343 mol
• Oxygen moles = 0.082 g / 16.00 g/mol = 0.00513 mol
  

Next, we find the simplest ratio of moles of antimony to moles of oxygen by dividing by the smallest number of moles:

• Ratio of Antimony to Oxygen = 0.00343 mol / 0.00343 mol : 0.00513 mol / 0.00343 mol
• This simplifies to approximately 1 : 1.5

Since we cannot have half an atom in a formula, we multiply each number in the ratio by 2 to get whole numbers:

• 1 * 2 = 2
• 1.5 * 2 = 3
  

The simplest formula for the compound is then Sb₂O₃, which means the compound contains two atoms of antimony for every three atoms of oxygen.

Answer 2

To find the simplest formula for a compound, we need to determine the ratio of elements present. In this case, the empirical formula is Sb₂O₃.

Step-by-step explanation:

To determine the empirical formula of the compound, we need to find the ratio of the elements present. In this case, since we have the masses of antimony and oxygen, we can calculate the number of moles of each element. The number of moles of antimony is found by dividing the mass of antimony by its molar mass, while the same is done for oxygen. Once we have the moles of each element, we divide them by the smallest number of moles to get the simplest whole-number ratio. In this case, the ratio is 1:2, so the empirical formula is Sb₂O₃.