Answer:
(A) 28
Explanation:
To solve this problem we use the <em>PV=nRT equation</em>, where:
- P = 800 mmHg ⇒ 800/760 = 1.05 atm
- R = 0.082 atm·L·mol⁻¹·K⁻¹
- T = 25.0 °C ⇒ 25.0 + 273.16 = 298.16 K
We<u> input the data</u>:
- 1.05 atm * 2.00 L = n * 0.082 atm·L·mol⁻¹·K⁻¹ * 298.16 K
And <u>solve for n</u>:
Now we calculate the gas' mass:
- Gas Mass = (Mass of Container w/ Gas) - (Mass of Empty Container)
- Gas Mass = 1052.4 g - 1050.0 g = 2.4 g
Finally we <u>calculate the unknown gas' molar mas</u>s, using<em> its mass and its number of moles</em>:
- Molar Mass = mass / moles
- Molar Mass = 2.4 g / 0.086 mol = 27.9 g/mol
So the answer is option (A).
The alveoli are surrounded<span> by tiny blood vessels, called capillaries. The </span>alveoli<span> and capillaries both have very thin walls, which allow the oxygen to pass from the </span>alveoli<span>to the blood. The capillaries then connect to larger blood vessels, called veins, which bring the oxygenated blood from the lungs to the heart.</span>
<u>Answer:</u> The atomic mass of these species is different and atomic number remains same.
<u>Explanation:</u>
Isotopes are the chemical species of the same element having different number of neutrons.
- Atomic number is equal to the number of protons or electrons present in that element.
Atomic Number = Number of electrons = Number of protons
- Atomic mass is defined as the sum of number of protons and neutrons contained in an atom.
Atomic Mass = Number of protons + Number of neutrons
For isotopes, as the number of neutrons differ, the atomic mass also differs.
For Example: Carbon has 3 naturally occurring isotopes:
. The atomic number remains the same but atomic mass differs.
Hence, for isotopes, the atomic mass of these species is different and atomic number remains same.
Fossil fuels and unnatural energy sources still dominate in the US, this influences many problems including global warming, climate change, and pollution. Burning fossil fuels is also a problem to human health. And unnatural resources won’t be there forever whereas, renewable sources could last a long time.
<span>Sublimation: the substance changes directly from a solid to a gas without going through the liquid phase. Deposition: the substance changes directly from a gas to a solid without going through the liquid phase.</span>