Question

M(Mg) - 5г 2Mg + O2 = 2MgO m(O2) - ?

Answer 1

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Answer 2

2Mg + O₂ = 2MgO

n(Mg) = m ÷ M = 5г ÷ 24г\моль = 0.2 моль

n(Mg) = n(O₂) = 0.2 моль ÷ 2 = 0.1 моль

m(O₂) = n × M  = 0.1 моль × 32г\моль = 3.2г

Answer 3

To find the molar mass of O2 (molecular oxygen), we need to first calculate the molar mass of magnesium (Mg) and magnesium oxide (MgO).

Molar mass of Mg (molar mass of magnesium) = 24.305 g/mol Molar mass of MgO (molar mass of magnesium oxide) = 24.305 g/mol (Mg) + 15.999 g/mol (O) = 40.304 g/mol

Now, we have the balanced chemical equation: 2Mg + O2 → 2MgO

We know that 2 moles of magnesium (2Mg) react with 1 mole of oxygen gas (O2) to produce 2 moles of magnesium oxide (2MgO).

Given that the mass of magnesium (Mg) is 5g, we can calculate the moles of Mg using its molar mass:

Moles of Mg = Mass of Mg / Molar mass of Mg Moles of Mg = 5 g / 24.305 g/mol ≈ 0.206 moles

Now, since 2 moles of magnesium react with 1 mole of oxygen (O2), we can set up a proportion to find the moles of oxygen gas (O2):

0.206 moles of Mg / 2 moles of MgO = x moles of O2 / 1 mole of O2

x moles of O2 = 0.206 moles of Mg * (1 mole of O2 / 2 moles of MgO) x moles of O2 ≈ 0.206 moles * 0.5 ≈ 0.103 moles

Finally, let's find the mass of oxygen gas (O2) using its molar mass:

Mass of O2 = Moles of O2 * Molar mass of O2 Mass of O2 = 0.103 moles * 32.00 g/mol ≈ 3.296 g

So, the mass of oxygen gas (O2) required for the reaction is approximately 3.296 grams.