Question

A sample of Mg3 (PO4)2 contains 72g of Mg in the sample .calculate the number of g molecules of oxygen in the sample.​

Answer 1

Answer:

your answer is 64g dear

Explanation:

because the mass of one atom of oxygen is 16g so here given the four atoms of oxygen so we will multiply it to 4 so the answer will be 64 gm. hope it may be right dear

Answer 2

Answer:

The sample of Mg₃(PO₄)₂ contains 4 grams of oxygen molecules.

Explanation:

Mg₃(PO₄)₂ contained in the sample ⇒ 72 g

Number of moles of Mg contained in the sample = $\frac{weight of Magnesium}{ Molar mass of Magnesium }$

= $\frac{72}{24}$

= 3 mol

Number of moles of Oxygen in the sample = $4\times 2 = 8$ mol

Weight of Oxygen in the sample = Number of moles $\times$ molar mass of         oxygen = 8 $\times$ 16 = 128

Number of grams of Oxygen in the sample= $\frac{Weight of Oxygen in the sample}{Atomic weight}$

=$\frac{128}{32}$

= 4 g

The correct answer is 4 g.