WAEC - Chemistry (2023 - No. 13)
How many moles are there in 3.0 g of \(O_2\)? [O = 16.0]
0.0093 moles.
0.0930 moles.
0.0625 moles.
0.6250 moles.
설명
Number of moles = Mass / Molar mass
Given that the molar mass of oxygen \(O_2\) is 32.0 g/mol (2 × 16.0 g/mol), you can calculate the number of moles:
Number of moles = 3.0 g / 32.0 g/mol = 0.09375 moles
Rounded to four significant figures, the number of moles in 3.0 g of O2 is approximately 0.0938 moles.
Therefore, the closest answer choice is:
0.0930 moles.
Given that the molar mass of oxygen \(O_2\) is 32.0 g/mol (2 × 16.0 g/mol), you can calculate the number of moles:
Number of moles = 3.0 g / 32.0 g/mol = 0.09375 moles
Rounded to four significant figures, the number of moles in 3.0 g of O2 is approximately 0.0938 moles.
Therefore, the closest answer choice is:
0.0930 moles.