Answer:
31.60% phosphorus
Explanation:
To find the percent by mass, you first calculate the total mass and then the mass of phosphorus, and finally divide phosphorus mass by total.
Phosphorus mass: the molar mass of P is 30.97 g/mol, and since there's 1 mole of P, we just have 30.97 g.
Total mass: we add all the molar masses of the components together.
We have 3 moles of H, so we multiply 3 by 1.008 g/mol = 3.024 g H.
We already calculated the mass of phosphorus: 30.97 g P.
We have 4 moles of O, so we multiply 4 by 16.00 g/mol = 64.00 g O.
The total is then the sum: 3.024 + 30.97 + 64.00 = 97.994 g ≈ 97.99 g
Now, to find the percentage, we take 30.97 g P and divide by 97.99:
30.97/97.99 ≈ 0.3160 ⇒ 31.60% P
Thus, the answer is 31.60% phosphorus.
Hope this helps!
Density = mass/volume
density = 81 grams/0.9 cubic centimetersdensity = 90 grams per cubic centimeter
The density of the sample is 90 grams per cubic centimeter.
Answer:
To calculate the volume we must first find the number of moles
Number of moles (n ) = mass / Molar mass (M)
Since oxygen is diatomic
M of oxygen = 16 × 2 = 32g/mol
n = 16 / 32 = 0.5mol
Next we use the formula
V = n × V(dm³)
where V is the volume
V(dm³) is the volume of 1 mole of a substance at s.t.p which is
22.4dm³
Volume of oxygen gas at s.t.p is
0.5 × 22.4dm³
= 11.20dm³
Hope this helps you
Answer:
A
Explanation:
this is because the electrons are attracted to the protons, the stronger the attraction and energy level the closer the electrons are to the nucleus. this moves them to a higher energy orbital. For example in a Bohr diagram.
