how many oxygen atoms are in 773.2g of carbon dioxide? and also what is the molar mass of an element where 3.4 moles of the element has a mass of 669.69g? which elent is it?
To determine the number of oxygen atoms in 773.2 g of carbon dioxide, we need to use the concept of molar mass and Avogadro's number.
1. Carbon dioxide (CO2) has one carbon atom (C) and two oxygen atoms (O).
2. To find the molar mass of carbon dioxide, we need to add the atomic masses of carbon and oxygen. The atomic mass of carbon (C) is approximately 12.01 g/mol, and the atomic mass of oxygen (O) is approximately 16.00 g/mol.
Molar mass of carbon dioxide (CO2) = (12.01 g/mol * 1) + (16.00 g/mol * 2) = 44.01 g/mol
3. Now, we can calculate the number of moles of carbon dioxide using its molar mass:
Moles of CO2 = Mass of CO2 / Molar mass of CO2
= 773.2 g / 44.01 g/mol
≈ 17.56 mol
4. Since each molecule of CO2 contains 2 oxygen atoms, we can multiply the number of moles by Avogadro's number to determine the number of oxygen atoms:
Number of oxygen atoms = Moles of CO2 * Avogadro's number * 2
= 17.56 mol * 6.02 x 10^23 * 2
≈ 2.12 x 10^25 oxygen atoms
Therefore, there are approximately 2.12 x 10^25 oxygen atoms in 773.2 g of carbon dioxide.
To find the molar mass of an element and identify which element it is based on the given information:
1. Divide the given mass of the element (669.69 g) by the number of moles (3.4 moles):
Molar mass of the element = Mass of the element / Moles of the element
= 669.69 g / 3.4 mol
≈ 196.97 g/mol
2. Now, we need to identify the element with the closest molar mass to 196.97 g/mol. The element with a molar mass of approximately 196.97 g/mol is Gold (Au).
Therefore, the element is Gold (Au) with a molar mass of approximately 196.97 g/mol.