I need help on chemistry work

For the reaction 2N2O5(g) <---> 4NO2(g) + O2(g), the following data were colected:

KonstantinChe [14]

Answer:

a) The reaction is first order, that is, order 1. Option C is correct.

b) The half life of the reaction is 23 minutes. Option B is correct

c) The initial rate of production of NO2 for this reaction is approximately = (3.7 × 10⁻⁴) M/min. Option has been cut off.

Explanation:

First of, we try to obtain the order of the reaction from the data provided.

t (minutes) [N2O5] (mol/L)

0 1.24x10-2

10 0.92x10-2

20 0.68x10-2

30 0.50x10-2

40 0.37x10-2

50 0.28x10-2

70 0.15x10-2

Using a trial and error mode, we try to obtain the order of the reaction. But let's define some terms.

C₀ = Initial concentration of the reactant

C = concentration of the reactant at any time.

k = rate constant

t = time since the reaction started

T(1/2) = half life

We Start from the first guess of zero order.

For a zero order reaction, the general equation is

C₀ - C = kt

k = (C₀ - C)/t

If the reaction is indeed a zero order reaction, the value of k we will obtain will be the same all through the set of data provided.

C₀ = 0.0124 M

At t = 10 minutes, C = 0.0092 M

k = (0.0124 - 0.0092)/10 = 0.00032 M/min

At t = 20 minutes, C = 0.0068 M

k = (0.0124 - 0.0068)/20 = 0.00028 M/min

At t = 30 minutes, C = 0.0050 M

k = (0.0124 - 0.005)/30 = 0.00024 M/min

It's evident the value of k isn't the same for the first 3 trials, hence, the reaction isn't a zero order reaction.

We try first order next, for first order reaction

In (C₀/C) = kt

k = [In (C₀/C)]/t

C₀ = 0.0124 M

At t = 10 minutes, C = 0.0092 M

k = [In (0.0124/0.0092)]/10 = 0.0298 /min

At t = 20 minutes, C = 0.0068 M

k = 0.030 /min

At t = 30 minutes, C = 0.0050 M

k = 0.0303

At t = 40 minutes

k = 0.0302 /min

At t = 50 minutes,

k = 0.0298 /min

At t = 60 minutes,

k = 0.031 /min

This shows that the reaction is indeed first order because all the answers obtained hover around the same value.

The rate constant to be taken will be the average of them all.

Average k = 0.0302 /min.

b) The half life of a first order reaction is related to the rate constant through this relation

T(1/2) = (In 2)/k

T(1/2) = (In 2)/0.0302

T(1/2) = 22.95 minutes = 23 minutes.

c) The initial rate of production of the product at the start of the reaction

Rate = kC (first order)

At the start of the reaction C = C₀ = 0.0124M and k = 0.0302 /min

Rate = 0.0302 × 0.0124 = 0.000374 M/min = (3.74 × 10⁻⁴) M/min

3 0

3 years ago

Calculate the number of moles of a gas that is present in a 7.55 L container at 45°C, if the gas exerts a pressure of 725mm Hg.

vovikov84 [41]

Answer: The number of moles of gas present is 0.276 moles

Explanation:

To calculate the number of moles of gas, we use the equation given by ideal gas:

PV = nRT

where,

P = Pressure of the gas = 725 mm Hg

V = Volume of the gas = 7.55 L

n = number of moles of gas = ?

R = Gas constant = $62.3637\text{ L.mmHg }mol^{-1}K^{-1}$

T = Temperature of the gas = $45^oC=(45+273)K=318K$

Putting values in above equation, we get:

$725mmHg\times 7.55L=n\times 62.3637\text{ L.mmHg }mol^{-1}K^{-1}\times 318K\\\\n=0.276mol$

Hence, the number of moles of gas present is 0.276 moles

4 0

3 years ago

Calculate the frequency of light having a wavelength of 425nm. remember that 1nm=1×10−9m

Gnom [1K]

The frequency of light having a wavelength of 425nm will be 70588 × $10^{14} Hz$ .

The count of times an event takes place per unit of time is known as its frequency. The word frequency would be most frequently used to describe waves in physics including chemistry, including light, sound, including radio waves. The frequency refers to the number of times during one second that a point on a wave crosses a fixed reference point.

A waveform signal that is carried in space or down a wire has a wavelength, which is the separation between two identical places in the consecutive cycles.

Given data:

wavelength = 425nm = $425 * 10^{-9} m$

Frequency can be calculated by using the formula;

Frequency = speed of light / wavelength

Frequency = 3 × $10^{8} m/s$ / 425 × $10^{-9} m$ = 7,0588 × $10^{14} Hz$ .

Therefore, the frequency of light having a wavelength of 425nm will be 70588 × $10^{14} Hz$ .

To know more about frequency

brainly.com/question/18651058

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8 0

2 years ago

Why does the pressure inside a container of gas increase?

yan [13]

Pressure is a scientific parameter that allows us to determine the amount of force being exerted per unit area. The increase in the pressure inside a container containing a gas may be brought upon by the decrease in volume, increase in temperature, or merely by additional of more gas molecules.

3 0

3 years ago

HELP NEEDED How many nanoliters are in 1 liter. Show work

DochEvi [55]

1 000 000 000 nanoliters

7 0

3 years ago

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