Answer:
5 moles of oxygen are required.
Explanation:
Given data:
Moles of O₂ required = ?
Moles of H₂ present = 10 mol
Solution:
Chemical equation:
O₂ + 2H₂ → 2H₂O
Now we will compare the moles of oxygen and hydrogen.
H₂ : O₂
2 : 1
10 : 1/2×10 = 5 mol
5 moles of oxygen are required.
Answer: 72.41% and 26.90% respectively.
Explanation:
At 60°C, you can dissolve 46.4g of acetanilide in 100mL of ethanol. If you lower the temperature, at 0°C, you can dissolve just 12.8g, which means (46.4g-12.8g)=33.6g of acetanilide must have precipitated from the solution.
We can calculate recovery as:

So the answer to the first question is 72.41%.
For the second part just use the same formula, the mass of the precipitate is the final mass minus the initial mass, (171mg-125mg)=46mg.

So the answer to the second question is 26.90%.
Answer:
trigonal planar
Explanation:
The molecule SO3 is of the type AX3. The molecule is symmetrical and non polar.
There are three regions of electron density in the molecule. This corresponds to a trigonal planar geometry. This means that the three oxygen atoms are arranged at the corners of a triangle. The bond angle is 120 degrees.
Explanation:
Due to the positive value of the change in temperature, this is an endothermic reaction.
Since the forward reaction is endothermic, increasing the temperature increases the equilibrium constant (k).
In an equilibrium system, the position of the equilibrium will move in a way to annul the change made to the system. An increase in temperature for an endothermic reaction would favour the reaction, leading to increase in amount of products and decrease in amount of reactants.
Answer:
The order of elements by volume-fraction (which is approximately molecular mole-fraction) in the atmosphere is nitrogen (78.1%), oxygen (20.9%), argon (0.96%), followed by (in uncertain order) carbon and hydrogen because water vapor and carbon dioxide, which represent most of these two elements in the air, are variable.
I copied and pasted but I hope this information is helpful :)