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
Answer: -
The hydrogen at 10 °C has slower-moving molecules than the sample at 350 K.
Explanation: -
Temperature of the hydrogen gas first sample = 10 °C.
Temperature in kelvin scale of the first sample = 10 + 273 = 283 K
For the second sample, the temperature is 350 K.
Thus we see the second sample of the hydrogen gas more temperature than the first sample.
We know from the kinetic theory of gases that
The kinetic energy of gas molecules increases with the increase in temperature of the gas. The speed of the movement of gas molecules also increase with the increase in kinetic energy.
So higher the temperature of a gas, more is the kinetic energy and more is the movement speed of the gas molecules.
Thus the hydrogen at 10 °C has slower-moving molecules than the sample at 350 K.
Answer:
A
Explanation:
the correct answer is A
This is the sidereal month. It is measured against the background stars. However, the Earth is also orbiting the Sun, and the moon needs extra time to catch up to its previous position relative to the Sun.
Carbon-16 has 10 Neutrons.
The balanced chemical reaction is :
Number of moles of Na, 
.
Now, from balance chemical reaction we can see that 1 mole of oxygen reacts with 4 moles of sodium.
So, number of moles of oxygen are :
So, amount of oxygen required is :
Therefore, 5.08 gram of oxygen will react with 14.6 gram of sodium.
