Answer:
The statement that is not true is: 'Temperature does not affect the reaction rate'.
Explanation:
a) Temperature can change a reaction rate. <u> This is true</u>
Increasing the temperature increases the reaction rates because of the disproportionately large increase in the number of high energy collisions. It is only these collisions (possessing at least the activation energy for the reaction) which result in a reaction.
For example, the time taken to melt a metal will be much higher at a lower temperature but it will decrease as soon as we increase the temperature
b) The amount of reactants can increase the reaction rate.<u> This is true</u>
A higher concentration of reactants leads to more effective collisions per unit time, which leads to an increased reaction rate.
c) Temperature can decrease the reaction rate. <u>This is true </u>
Decreasing the temperature decreases the reaction rates because of the decrease in the number of high energy collisions. It will result in a slower reaction.
d) Temperature does not affect the reaction rate. <u>This is not true. </u>
The reaction rate is temperature dependent. The reaction rate increases with higher temperature and decreases with lower temperature.
Answer:
Dark Matter
Explanation:
90 percent of the mass in the universe is dark matter
When scientists say that a theory can never be proven it is always possible for a new data to contradict a theory
Answer:
The mole fraction of hexane is 0.61
Explanation:
Raoult's law allows calculating the vapor pressure of a substance when it is forming part of an ideal solution, knowing its vapor pressure when it is pure (at the same temperature) and the composition of the ideal solution in terms of mole fraction.
Pi=xi*Pi°
where Pi is the partial pressure of component i in the solution, Pi ° is the vapor pressure of component i pure and xi is the mole fraction of component i in the liquid phase.
In a solution, once the components have reached chemical equilibrium, the total vapor pressure is:
Psolution=P1 + P2=x1*P1° +x2*P2°
In this case:
Psolution= xpentane*Ppentane° +xhexane*Phexane°
Being:
- Psolution= 258 torr
- xpentane + xhexane=1 ⇒ xpentane= 1 - xhexane
- Ppentane°= 425 torr
- xhexane= ?
- Phexane°= 151 torr
and replacing:
258 torr= (1-xhexane)* 425 torr + xhexane* 151 torr
you get:
258 torr= 425 torr - 425 torr*xhexane + xhexane* 151 torr
258 torr - 425 torr= - 425 torr*xhexane + xhexane* 151 torr
-167 torr= -274 torr*xhexane
xhexane= 0.61
<u><em>The mole fraction of hexane is 0.61</em></u>
Use the Keq equation.. concentraion of products divided by concentration of reactants at equilibrium. (with coefficients as exponents, none in this case reaction is balanced)
Keq = [PCl5] / ([PCl3] [Cl2])
fill in given values and solve for [Cl2] using algebra. Im just going to sub in "c" for the unknown.
0.00094 = 0.44 / 0.33c
0.0003102c = 0.44
c = 1418.44 mol/L