O = 16 g/mol
Mg = 24 g/mol
so
mass MgO/mass Mg = (24+16)/24
mass MgO = 24 (24+16)/24 = 40 grams
2Mg+O2 = 2MgO
Mass of magnesium oxide formed by buring 24g of magnesium in air is
a.16g
b.80g
c.20g
d.40g
Mg = 24 g/mol
so
mass MgO/mass Mg = (24+16)/24
mass MgO = 24 (24+16)/24 = 40 grams
The balanced equation is:
2Mg + O2 -> 2MgO
From the equation, we can see that 2 moles of magnesium react with 1 mole of oxygen gas to produce 2 moles of magnesium oxide.
To determine the mass of magnesium oxide produced, we can follow these steps:
Step 1: Calculate the molar mass of magnesium oxide (MgO).
- The molar mass of Mg = 24.31 g/mol
- The molar mass of O = 16.00 g/mol
- Molar mass of MgO = (24.31 g/mol) + (16.00 g/mol) = 40.31 g/mol
Step 2: Convert the given mass of magnesium (24g) to moles.
- Moles of Mg = Mass of Mg / Molar mass of Mg = 24g / 24.31 g/mol ≈ 0.99 moles
Step 3: Use the mole ratio from the balanced equation to determine the moles of magnesium oxide produced.
- According to the stoichiometry, 2 moles of Mg produce 2 moles of MgO.
- Thus, 0.99 moles of Mg will produce the same number (0.99 moles) of MgO.
Step 4: Convert the moles of MgO to grams.
- Mass of MgO = Moles of MgO x Molar mass of MgO = 0.99 moles x 40.31 g/mol ≈ 39.90 g
Therefore, the mass of magnesium oxide formed by burning 24g of magnesium is approximately 39.90g.
None of the answer choices (a, b, c, or d) match the calculated value. It's possible that the given answer choices are rounded approximations, or there may be an error in the question or answer choices.