Question

What is the empirical formula of your product? Mg O

Percent Mass of the magnesium present is

Trial 1: 54.9%

Trial 2: 54.3%

Percent mass of the oxygen present is:

Trial 1: 45.1%

Trial 2: 45.7%

The answer is Mg4O5 I need help with how to get that , thank you!

Answer 1

Step-1 The unbalanced equations are for this question is are as under

Mg(s) + N₂(g) + O₂(g) → MgO(s) + Mg₃N₂(s)

MgO(s) + Mg₃N₂(s) + H₂O(l) → MgO(s) + Mg(OH)₂(s) + NH₃(g)

MgO(s) + Mg(OH)₂(s) → Mg_xO_y(s) + H₂O(g)

Step-2

Balancing the reactions is not necessary because the theoretical reaction product and yield is based on the amount of Mg available to react. The expected product is MgO, so the 1-to-1 mole ratio Mg to O in the product is all that is required

Step-3

Based on the masses of the solid reactant (Mg) and product (Mg_xO_y), the mass in grams and the amount in moles of Mg and O in the product can be determined. Recall that the conversion factor relating grams to moles is molar mass.

Step-4

This is general equation of moalr mass are as under

mass of Mg + mass of O = mass of Mg_xO_y

Now above equation also write are as under

mass of O = mass of Mg_xO_y − mass of Mg

mol Mg = w grams Mg ×

1 mol Mg

24.31 g Mg

mol O = z grams O ×

1 mol O

16.00 g O

where w is the grams of Mg used and z is the grams of O incorporated.The empirical formula of magnesium oxide, Mg_xO_y, is written as the lowest whole-number ratio between the moles of Mg used and moles of O consumed. This is found by determining the moles of Mg and O in the product; divide each value by the smaller number; and, multiply the resulting values by small whole numbers (up to five) until you get whole number values (with 0.1 of a whole number).

Step-5

Explain in 5 step with example

For example, if 0.0109 moles of Mg are combined with 0.0103 moles of O:

Mg_{0.0109/0.0103}O_{0.0103/0.0103} = Mg_1.06O_1.00 ⇒ no need to multiply ⇒ MgO

For example, if 0.0129 moles of Mg are combined with 0.0103 moles of O:

Mg_{0.0129/0.0103}O_{0.0103/0.0103} = Mg_1.25O_1.00 ⇒ multiply by 4 ⇒ (Mg_1.25O_1.00)₄ ⇒ Mg₅O₄

The correct answer of this equation is

Mg₅O₄

this is not equal to the Mg4O5

Thank you,

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