Question

The compound A2O is 63.7% A (mystery element) and 36.3% oxygen. What is the identity of element A?

Answer 1

To determine the identity of element A in the compound A2O, we can use the percent composition of the compound. By using the atomic mass of element A and the percent composition, we can identify the element.

Step-by-step explanation:

To determine the identity of element A in the compound A2O, we can use the percent composition of the compound. Since the compound is 63.7% A and 36.3% oxygen, we can assume that the percent composition represents the mass of each element in the compound. Therefore, if we assume a 100g sample of the compound, we would have 63.7g of element A and 36.3g of oxygen.

Since we now know the mass of element A in the compound, we can use the atomic mass of element A to determine the number of moles of element A. By dividing the mass of element A by its atomic mass, we can find the number of moles.

Finally, referencing the periodic table, we can identify the element A based on its atomic mass. Therefore, the identity of element A in the compound A2O is determined by its atomic mass and can be found by using the percent composition and the atomic mass.

Answer 2

Nitrogen,N

Step-by-step explanation:

We are given;

• Formula of the compound as A₂O
• % of A is 63.7%
• % of Oxygen is 36.3%

We are required to identify A

• First we are going to determine the mass of O in the compound

Atomic mass of O is 16.00 g

Therefore, mass of Oxygen in the compound is 16.00 g

• Second, we can determine the mass of A in the compound

16.00 g = 36.3 %

Thus, mass of A = (16.00 × 63.7%) ÷ 36.3%

= 28.077 g

But there are two atoms of A in the compound

Therefore, Atomic mass of A = 28.077 g ÷ 2

= 14.039 g

= 14.0 g

Thus, the identity of element A is nitrogen, because its atomic number is 14.0067 which is approximately 14.0 g

Hence, identity of element A is Nitrogen (N)