Answer:
B
Explanation:
Noble gases are in group 18 (neon, argon, etc)
Answer:
3.74g of ethylene glycol must be added to decrease the freezing point by 0.400°C
Explanation:
One colligative property is the freezing point depression due the addition of a solute. The equation is:
ΔT=Kf*m*i
<em>Where ΔT is change in temperature = 0.400°C</em>
<em>Kf is freezing point constant of the solvent = 1.86°C/m</em>
<em>m is molality of the solution (Moles of solute / kg of solvent)</em>
<em>And i is Van't Hoff constant (1 for a nonelectrolyte)</em>
Replacing:
0.400°C =1.86°C/m*m*1
0.400°C / 1.86°C/m*1 = 0.215m
As mass of solvent is 280.0g = 0.2800kg, the moles of the solute are:
0.2800kg * (0.215moles / 1kg) = 0.0602 moles of solute must be added.
The mass of ethylene glycol must be added is:
0.0602 moles * (62.10g / mol) =
3.74g of ethylene glycol must be added to decrease the freezing point by 0.400°C
<em />
the answer is: Atomic number
Answer:
0.14 moles of Fe₂O₃
Explanation:
Given parameters:
Number of moles of Fe = 0.27moles
Unknown:
Number of moles of Fe₂O₃ = ?
Solution:
To solve this problem, we are going to the work from the known specie to the unknown using their number of moles.
We first obtain the balanced equation of the reaction;
4Fe + 3O₂ → 2Fe₂O₃
The equation above is balanced;
4 moles of Fe produced 2 moles of Fe₂O₃
0.27 moles of Fe will produce 
= 0.14 moles of Fe₂O₃
Answer: Endothermic reaction.
Explanation: A chemical reaction in which energy is absorbed from the surrounding environment.
