Answer:
C. effusion because there is a movement of a gas through a small opening into a larger volume
Explanation:
Effusion makes fluid/gas molecules move to the container with less pressure or larger volume. In diffusion, the movement should work two ways even though one side might receive more. But in effusion, the movement is rather one way.
This case shows how effusion work because its not the concentration that makes the balls moving to the bottom part of the container. No ball moving from bottom container to top either.
<h3>Answer:</h3>
0.8133 mol
<h3>Solution:</h3>
Data Given:
Moles = n = ??
Temperature = T = 25 °C + 273.15 = 298.15 K
Pressure = P = 96.8 kPa = 0.955 atm
Volume = V = 20.0 L
Formula Used:
Let's assume that the Argon gas is acting as an Ideal gas, then according to Ideal Gas Equation,
P V = n R T
where; R = Universal Gas Constant = 0.082057 atm.L.mol⁻¹.K⁻¹
Solving Equation for n,
n = P V / R T
Putting Values,
n = (0.955 atm × 20.0 L) ÷ (0.082057 atm.L.mol⁻¹.K⁻¹ × 298.15 K)
n = 0.8133 mol
<span>MoO2
First, lookup the atomic weights of the elements involved
Atomic weight molybdenum = 95.94
Atomic weight oxygen = 15.999
Now calculate the molar mass of Mo2O3
2 * 95.94 + 3 * 15.999 = 239.877 g/mol
Now determine how many moles of the original Mo2O3 you had
10.63 g / 239.877 g/mol = 0.044314378 mol
Determine how much oxygen was added
11.340 g - 10.63 g = 0.71 g
How many moles of oxygen was added
0.71 g / 15.999 g/mol = 0.044377774 mol
Looking at the number of moles of oxygen added and the number of moles of the original compound, they're the same. So 1 oxygen atom was added to each molecule. Since the formula was Mo2O3, the new formula becomes Mo2O4. But since you're looking for the empirical formula, you need to reduce it. Both 2 and 4 are evenly divisible by 2, so the empirical formula becomes MoO2</span>
Answer:
The evidence showing that there is a chemical reaction taking place is the instantaneous temperature drop once the cold pack is shaken.
Explanation:
When an athlete applies a cold pack to the injury, they shake it before, mixing the water and <em>ammonium-nitrate fertilizer</em> inside the cold pack. This mixing is an endothermic reaction, which means it absorbs heat. In turn, the temperature falls to 35 F for around 10 minutes.
The sample is most likely lead with lighter substances in it. Pure lead would be closer to the pure lead density, and heavier substances would make the density more, not less.
