B. i took the test and got it right
<span>(15.0 g) / (150.0 g) x (100 g) = 10.0 g/100 g H2O </span>
Answer:
Highest speed: He
Lowest speed: CO2
Explanation:
The rms speed (average speed) of the molecules/atoms in an ideal gas is given by:

where
R is the gas constant
T is the absolute temperature of the gas
M is the molar mass of the gas, which is the mass of the gas per unit mole
From the equation, we see that at equal temperatures, the speed of the molecules in the gas is inversely proportional to the molar mass: the higher the molar mass, the lower the speed, and vice-versa.
In this problem, we have 5 gases:
(CO2) (O2) (He) (N2) (CH4)
Their molar mass is:
CO2: 44 g/mol
O2: 16 g/mol
He: 4 g/mol
N2: 14 g/mol
CH4: 16 g/mol
The gas with lowest molar mass is Helium (He): therefore, this is the gas with greatest average speed.
The gas with highest molar mass is CO2: therefore, this is the gas with lowest average speed.
137 K
The volume is constant, so you can use <em>Gay-Lussac’s Pressure-Temperature Law </em>to calculate the new temperature (you don’t have to use the number of moles).
P1/T1 = P2/T2
Solve for T2: T2= T1 x P2/P1
P1 = 1.83 atm; T1 = 122 K
P2 = 2.05 atm; T2 = ?
∴ T2 = 122 K x (2.05 atm)/(1.83 atm) = 137 K
This result makes sense. Temperature is directly proportional to pressure. You increased the pressure by about 10 %, so the temperature increased by about 10 %.
Answer:
Adenosine triphosphate
In science, ATP stands for adenosine triphosphate. This chemical, discovered in the 1920s, is important to all life. It stores and releases energy for many cellular processes. It is found in mitochondria.
Explanation: