A 2.077g sample of an element which has an atomic mass between 40 and 55 reacts with oxygen to form 3.708g of an oxide. Determine the formula mass of oxide ( and identify the element)

This is done the same way as the M2S3/MO2 problem. See that solution above.

To determine the formula mass of the oxide formed and identify the element, we need to first calculate the number of moles of the element and the number of moles of oxygen in the oxide.

1. Calculate the number of moles of the element (M):
- Given mass of the element = 2.077 g
- Atomic mass range of the element = 40 to 55 g/mol
- Let's assume the atomic mass of the element is M
- Using the formula: moles = mass / molar mass
- Number of moles of the element = 2.077 g / M g/mol

2. Calculate the number of moles of oxygen in the oxide:
- Given mass of the oxide = 3.708 g
- Assume the formula of the oxide is "XO" (where X represents the element)
- Calculate the molar mass of oxygen (O):
- Atomic mass of oxygen (O) = 16 g/mol
- Using the formula: moles = mass / molar mass
- Number of moles of oxygen = 3.708 g / 16 g/mol

3. From the chemical reaction, we know that the ratio of the element to oxygen in the oxide is 1:1.

4. Equate the moles of the element and oxygen in the oxide:
- Number of moles of element = Number of moles of oxygen
- 2.077 g / M g/mol = 3.708 g / 16 g/mol

5. Solve for M:
- Cross-multiply and solve for M:
- (2.077 g) * (16 g/mol) = (3.708 g) * M g/mol
- 33.232 g/mol = 3.708 M g/mol
- M = 33.232 g/mol / 3.708 g/mol
- M ≈ 8.956 g/mol

The formula mass of the oxide is approximately 8.956 g/mol, and the element that forms it has an atomic mass between 40 and 55.

To determine the formula mass of the oxide and identify the element, we need to use the given masses and atomic mass range.

1. Determine the number of moles of the element:
Using the formula:
Number of moles = mass / atomic mass

Given: Mass = 2.077g
Atomic mass range: 40-55

To find the atomic mass, we need to take into account the range and calculate the average:

Atomic mass = (40 + 55) / 2 = 47.5

Number of moles = 2.077g / 47.5g/mol ≈ 0.044 mol

2. Determine the number of moles of oxygen:
Since the mass of the oxide is given, we can subtract the mass of the element to find the mass of oxygen:

Mass of oxygen = Mass of oxide - Mass of element
= 3.708g - 2.077g
= 1.631g

Number of moles of oxygen = mass / atomic mass

Assuming oxygen has an atomic mass of ~16g/mol:
Number of moles of oxygen = 1.631g / 16g/mol ≈ 0.102 mol

3. Determine the simplest whole-number ratio of the element to oxygen:
To determine the ratio between the element and oxygen, divide the number of moles by the smaller number of moles:

Element: 0.044 mol / 0.044 mol ≈ 1
Oxygen: 0.102 mol / 0.044 mol ≈ 2.32

Rounding to the nearest whole number, the ratio becomes:
Element: 1
Oxygen: 2

4. Determine the formula mass of the oxide:
The formula mass is the sum of the atomic masses of all the atoms in the formula. Since the ratio is 1:2, the formula of the oxide is EO2, where E represents the element.

Formula mass = (atomic mass of element) + (2 x atomic mass of oxygen)

Using the atomic weight of the element (47.5 g/mol) and the atomic weight of oxygen (~16 g/mol):
Formula mass = 47.5g/mol + (2 x 16g/mol)
= 47.5g/mol + 32g/mol
= 79.5g/mol

Therefore, the formula mass of the oxide is 79.5 g/mol, and based on the given information, we cannot determine the specific identity of the element.