Answer:
T = 246 K
Explanation:
Given that,
Number of moles, n = 0.750 mol
The volume of the cylinder, V = 6850 mL = 6.85 L
Pressure of the gas, P = 2.21 atm
We need to find the temperature of the gas stored in the cylinder. We know that,
PV= nRT
Where
R is gas constant
T is temperature
So,
or
T = 246 K
So, the temperature of the gas is equal to 246 K.
Prominent copper sulfide minerals include Cu2S (chalcocite) and CuS (covellite).
Left Panel
A is an acid. Not the answer.
B is correct. That would be a base. But it is not an Arrhenius base. Keep reading.
C that is exactly what an Arrhenius base is.
D. No an acid of some sort would accept OH ions.
Right Panel
D is concentrated and it is also a weak base. Good cleaning fluid. Smells awful but it works.
To determine which order of the reaction it is, first we need to calculate the rate of change of moles.
the data is as follows
time 0 40 80 120 160
moles 0.100 0.067 0.045 0.030 0.020
Q1)
for the first 40 s change of moles ;
= -d[A] / t
= - (0.067-0.100)/40s
= 8.25 x 10⁻⁴ mol/s
for the next 40 s
= -(0.045-0.067)/40
= 5.5 x 10⁻⁴ mol/s
the 40 s after that
= -(0.030-0.045)/40 s
= 3.75 x 10⁻⁴ mol/s
k - rate constant
and A is the only reactant that affects the rate of the reaction
rate = k [A]ᵇ
8.25 × 10⁻⁴ mol/s = k [0.100 mol]ᵇ ----1
5.5 x 10⁻⁴ mol/s = k [0.067 mol]ᵇ -----2
divide the 2nd equation by the 1st equation
1.5 = [1.49]ᵇ
b is almost equal to 1
Therefore this is a first order reaction
Q2)
to find out the rate constant(k), we have to first state the equation for a first order reaction.
rate = k[A]ᵇ
As A is the only reactant thats considered for the rate equation.
Since this is a first order reaction,
b = 1
therefore the reaction is
rate = k[A]
substituting the values,
8.25 x 10⁻⁴ mol/s = k [0.100 mol]
k = 8.25 x 10⁻⁴ mol/s /0.100mol
= 8.25 x 10⁻³ s⁻¹
