<h3>
Answer:</h3>
298.15 K
<h3>
Explanation:</h3>
W e are supposed to calculate the Value of K at 25°C
Assuming the value of K represent K, the question wants us to convert degree Celsius to Kelvin.
- To convert degrees Celsius to kelvin scale, we use the relationship;
- Kelvin (K) = Degrees Celsius + 273.15 ; 273.5 is a constant
- That is, to convert temperature from °C to Kelvin we add a constant of 273.15 to the °C given.
In this case;
Temperature is 273.15 °c
Thus, to Kelvin scale temperature will be;
= 25°C + 273.15
= 298.15 K
Therefore, the value of K, at 25°C is 298.15 K
Then we would not have oxygen because plants give oxygen in order to breathe
Answer:
Hydrogen Chloride Gas is heavier than air and sinks to the ground after being released. Firefighters closer to the ground will be subjected to significantly greater concentrations of hydrogen chloride gas than the firefighters walking on top of railcars.
Explanation:
The molar mass of air is 28.97 g/mol. Air is approximately 78% N2, which has a molar mass of 28.014 g/mol and 21% oxygen, which has a molar mass of 32 g/mol; the remaining constituents of air include CO2 and other trace amounts of gases.
The molar mass of HCl is 36.458 g/mol.
Because HCl is heavier than air, it sinks toward the ground, displacing the lighter air.
The height of railway cars is reported to vary between 13.5 ft to 15.5 ft. So firefighters on tank cars are generally above the HCl gas (although localized atmospheric conditions could cause the HCl to move higher up in the air column).
Answer:
Two electrons
Explanation:
According to the octet rule, atoms must bond to each other, sharing electrons among themselves in an attempt to complete their valence shell (last layer of the electrosphere). In other words, an atom becomes stable when it has 8 electrons in its valence shell.
Oxygen atoms have six electrons in their valence shell, so to achieve the stability suggested by the octet rule (eight electrons), these atoms share two electrons, forming one oxygen gas (O₂) molecule.
Molar mass H₂O = 18.0 g/mol
number of moles :
1.0 / 18.0 => 0.055 moles
1 mole -------------- 6.02 x 10²³ molecules
0.055 moles -------- ? molecules
molecules = 0.055 x ( 6.02 x 10²³) / 1
molecules = 3.311x10²² / 1
= 3.311 x 10²² molecules
hope this helps!
