Answer: a. 79.6 s
b. 44.3 s
c. 191 s
Explanation:
Expression for rate law for first order kinetics is given by:
where,
k = rate constant
t = age of sample
a = let initial amount of the reactant
a - x = amount left after decay process
a) for completion of half life:
Half life is the amount of time taken by a radioactive material to decay to half of its original value.
b) for completion of 32% of reaction
c) for completion of 81 % of reaction
Answer:
Explanation:
We have in this question the equilibrium
X ( g ) + Y ( g ) ⇆ Z ( g )
With the equilibrium contant Kp = pZ/(pX x pY)
The moment we change the concentration of Y, we are changing effectively the partial pressure of Y since pressure and concentration are directly proportional
pV = nRT ⇒ p = nRT/V and n/V is molarity.
Therefore we can calculate the reaction quotient Q
Qp = pZ/(pX x pY) = 1/ 1 x 0.5 atm = 2
Since Qp is greater than Kp the system proceeds from right to left.
We could also arrive to the same conclusion by applying LeChatelier´s principle which states that any disturbance in the equilibrium, the system will react in such a way to counteract the change to restore the equilibrium. Therefore, by having reduced the pressure of Y the system will react favoring the reactants side increasing some of the y pressure until restoring the equilibrium Kp = 1.
Add the Pressure of neon and argon that is 0.68 +0.35= 1.03
Total pressure that is 1.25 -1.03=0.22 atm
Answer:
81°C.
Explanation:
To solve this problem, we can use the relation:
<em>Q = m.c.ΔT,</em>
where, Q is the amount of heat released from water (Q = - 1200 J).
m is the mass of the water (m = 20.0 g).
c is the specific heat capacity of water (c of water = 4.186 J/g.°C).
ΔT is the difference between the initial and final temperature (ΔT = final T - initial T = final T - 95.0°C).
∵ Q = m.c.ΔT
∴ (- 1200 J) = (20.0 g)(4.186 J/g.°C)(final T - 95.0°C ).
(- 1200 J) = 83.72 final T - 7953.
∴ final T = (- 1200 J + 7953)/83.72 = 80.67°C ≅ 81.0°C.
<em>So, the right choice is: 81°C.</em>
Answer : The vapor pressure (in atm) of a solution is, 0.679 atm
Explanation : Given,
Mass of
= 1.00 kg = 1000 g
Moles of
= 3.68 mole
Molar mass of
= 18 g/mole
Vapor pressure of water = 0.692 atm
First we have to calculate the moles of
.

Now we have to calculate the mole fraction of 

Now we have to partial pressure of solution.
According to the Raoult's law,

where,
= vapor pressure of solution
= vapor pressure of water = 0.692 atm
= mole fraction of water = 0.938



Therefore, the vapor pressure (in atm) of a solution is, 0.679 atm