They contain the same number of molecules; however, the masses can differ depending on the molar masses of the substances.
Answer:
limiting reactant started with/limiting reactant needed=
= 3.5 mol/3.5 mol=1:1
Explanation:
2H2 + 1 O2 ---> 2 H2O
from reaction 2 mol 1 mol
given 3.5 mol 2.5 mol
needed 3.5 mol 1.75 mol
Excess reactant O2, Limiting reactant H2.
Limiting reactant will be used completely.
So, limiting reactant started with/limiting reactant needed=
= 3.5 mol/3.5 mol=1:1
Answer:
C.
Explanation:
I believe that it should be A and B.
Ideal solutions obey Raoult's law, which states that:
P_i = x_i*(P_pure)_i
where
P_i is the partial pressure of component i above a solution
x_i is the mole fraction of component i in the solution
(P_pure)_i is the vapor pressure of pure component i
In this case,
P_benzene = 0.59 * 745 torr = 439.6 torr
P_toluene = (1-0.59) * 290 torr = 118.9 torr
The total vapor pressure above the solution is the sum of the vapor pressures of the individual components:
P_total = (439.6 + 118.9) torr = 558.5 torr
Assuming the gas phase also behaves ideally, the partial pressure of each gas in the vapor phase is proportional to its molar concentration, so the mole fraction of toluene in the vapor phase is:
118.9 torr/558.5 torr = 0.213
