combustion of 0.356g of an unknown metal sample in oxygen gives 0.452g of an oxide in the form of mO2, Identify the unknown metal?
I think I would approach it this way.
.....M + O2 ==> MO2
...0.356g.......0.452
So you know oxygen = 0.452-0.356 = 0.096 g
Then I would calculate percent.
M = (0.356/0.452)*100 = 78.76%
O2 = (0.096/0.452)*100 = 21.24%
Take a 100 g sample which gives us
78.76g M
21.24 g oxygen.
Convert to moles.
moles M = 78.76/molar mass = ??
moles O = 21.24/16 = 1.3275.
We know moles M must be 1/2 of 1.3275 = ??
Then 79.76/molar mass = 1/2*1.3275 and solve for molar mass.
To identify the unknown metal, we need to use the information provided about the mass of the metal sample and the mass of the resulting oxide.
First, we need to determine the change in mass between the original metal sample and the resulting oxide:
Change in mass = Mass of resulting oxide - Mass of metal sample
Change in mass = 0.452g - 0.356g
Change in mass = 0.096g
The change in mass represents the mass of oxygen that combined with the metal to form the oxide. To find the molar mass of the metal, we need to convert the mass of the metal to moles by dividing it by the molar mass of oxygen.
The molar mass of oxygen (O2) is approximately 32 g/mol.
Moles of oxygen = Mass of oxygen / Molar mass of oxygen
Moles of oxygen = 0.096g / 32 g/mol
Moles of oxygen = 0.003 mol
Now, since the metal reacts in a 1:1 ratio with oxygen to form the oxide, the moles of oxygen will also be the moles of the metal.
Moles of metal = 0.003 mol
To determine the molar mass of the metal, we divide the mass of the metal by its moles:
Molar mass of metal = Mass of metal / Moles of metal
Molar mass of metal = 0.356g / 0.003 mol
Performing this calculation, we find that the molar mass of the metal is approximately 118.67 g/mol.
To identify the unknown metal, we can compare its molar mass to values of known elements. Based on its molar mass of approximately 118.67 g/mol, the unknown metal corresponds to the element Tin (Sn).