All categories

2 years ago

For each reaction, find the value of ΔSo. Report the value with the appropriate sign. (a) 3 NO2(g) + H2O(l) → 2 HNO3(l) + NO(g)

Chemistry

1 answer:

aev [14]2 years ago

7 0

Answer:

ΔS° = -268.13 J/K

Explanation:

Let's consider the following balanced equation.

3 NO₂(g) + H₂O(l) → 2 HNO₃(l) + NO(g)

We can calculate the standard entropy change of a reaction (ΔS°) using the following expression:

ΔS° = ∑np.Sp° - ∑nr.Sr°

where,

ni are the moles of reactants and products

Si are the standard molar entropies of reactants and products

ΔS° = [2 mol × S°(HNO₃(l)) + 1 mol × S°(NO(g))] - [3 mol × S°(NO₂(g)) + 1 mol × S°(H₂O(l))]

ΔS° = [2 mol × 155.6 J/K.mol + 1 mol × 210.76 J/K.mol] - [3 mol × 240.06 J/K.mol + 1 mol × 69.91 J/k.mol]

ΔS° = -268.13 J/K

You might be interested in

A sealed vessel contains 0.200 mol of oxygen gas, 0.100 mol of nitrogen gas, and 0.200 mol of argon gas. The total pressure of t

babunello [35]

Answer:

Explanation:

We can use the mole ratio to calculate the partial pressure. The total number of moles is 0.2 + 0.2 + 0.1 = 0.5 moles

Now, we know that the mole fraction of the argon gas would be 0.2/0.5

The partial pressure is as follows. To calculate this, we simple multiply the number of moles by the total pressure.

0.2/0.5 * 5 = 1.0/0.5 = 2.00atm

8 0

2 years ago

You wish to make a buffer with pH 7.0. You combine 0.060 grams of acetic acid and 14.59 grams of sodium acetate and add water to

aleksandr82 [10.1K]

Answer:

The pH of the buffer is 7.0 and this pH is not useful to pH 7.0

Explanation:

The pH of a buffer is obtained by using H-H equation:

pH = pKa + log [A⁻] / [HA]

Where pH is the pH of the buffer

The pKa of acetic acid is 4.74.

[A⁻] could be taken as moles of sodium acetate (14.59g * (1mol / 82g) = 0.1779 moles

[HA] are the moles of acetic acid (0.060g * (1mol / 60g) = 0.001moles

Replacing:

pH = 4.74 + log [0.1779mol] / [0.001mol]

pH = 6.99 ≈ 7.0

The pH of the buffer is 7.0

But the buffer is not useful to pH = 7.0 because a buffer works between pKa±1 (For acetic acid: 3.74 - 5.74). As pH 7.0 is out of this interval,

this pH is not useful to pH 7.0

7 0

2 years ago

A copper rod that has a mass of 200.0 g has an initial temperature of 20.0°C and is heated to 40.0°C. If 1,540 J of heat are nee

Romashka [77]

Heat gained in a system can be calculated by multiplying the given mass to the specific heat capacity of the substance and the temperature difference. It is expressed as follows:

Heat = mC(T2-T1)

1540 = 200.0 (C)(40 - 20)

C = 0.385 J / g C

Hope this answers the question. Have a nice day.

8 0

2 years ago

Read 2 more answers

An empty beaker is weighed and found to weigh 23.1 g. Some potassium chloride is then added to the beaker and weighed again. The

GuDViN [60]

Answer:Mass of Potassium chloride =1.762g

Explanation:

Mass of empty beaker = 23.100 g

Mass of beaker with Potassium chloride = 24.862g

Mass of Potassium chloride = Final weight - initial weight = Mass of beaker with Potassium chloride - Mass of empty beaker = 24.862-23.100 = 1.762g

8 0

2 years ago

The end point of a titration is defined as the volume of titrant added, while the equivalence point is the volume required for c

natka813 [3]

Answer:

indicator

Explanation:

Indicators are the weak organic dyes which shows different colors in acidic and basic mediums.

Due to the fact that a noticeable pH change occurs near the equivalence point of acid-base titrations, an indicator can be used to signal the end point of a titration.

Therefore, choosing the proper indicator, scientists can minimize the difference in these two numbers, allowing more accurate measurements in the lab.

4 0

2 years ago