Answer:
The percentage by mass of element X is 25 %.
The percentage by mass of element Y is 75 %
Explanation:
X + Y ⇒ XY
3.5 g of element X + 10.5 g of element Y = 14g in total
⇒Element X : 3.5g / 14g = 0.25 ⇒ x 100 % = 25 %
⇒Element Y : 10.5 / 14 = 0.75 ⇒ x 100 % = 75 %
The percentage by mass of element X is 25 %.
The percentage by mass of element Y is 75 %
Answer:
D
Explanation:
Since the state of matter is going from a gas to a solid, it would be going from a state of high entropy (greater disorder) to a state of lower entropy (less disorder).
(99.63/100 x 14.003) + (0.37/100 x 15)
13.9511889 + 0.0555 = 14.0066889amu
13.95 + 0.0555 = 14.0055 (same thing just rounded numbers)
(You can round that to 14amu)
Answer is 14 amu