FORENSIC SCIENCE HELP

Calculate the standard entropy of vaporization of ethanol at its boiling point 285 K. The standard molar enthalpy of vaporizatio

Ivanshal [37]

Answer:

standard entropy of vaporization of ethanol = 142.105 J/K-mol

Explanation:

given data

enthalpy of vaporization of ethanol = 40.5 kJ/mol = 40.5 × $10^{3}$ J/mol

entropy of vaporization of ethanol boiling point = 285 K

to find out

standard entropy of vaporization of ethanol

solution

we get here standard entropy of vaporization of ethanol that is expess as

standard entropy of vaporization of ethanol ΔS = $\frac{\Delta H}{T}$ .............1

here ΔH is enthalpy of vaporization of ethanol and T is temperature

put value in equation 1

standard entropy of vaporization of ethanol ΔS = $\frac{40.5*10^3}{285}$

standard entropy of vaporization of ethanol = 142.105 J/K-mol

3 0

3 years ago

Read 2 more answers

2C8H18 (1) + 2502 (g) --> 16CO2 (g) + 18H2O (g)

Makovka662 [10]

Answer:

One gallon of octane produces approximately 7000 L of carbon dioxide.

Note:

I believe that the mass of octane should have been given as 2661 g. However, I understand that your instructor probably gave you this problem, so I will use 4000 g for the approximate mass of one gallon of octane. You can rework the problem on your own, substituting the correct masses of octane if you wish.

Step1. You must first determine the number of moles that are in 4000 g of octane, using the molar mass of octane. Step 2. Then you must determine the number of moles of carbon dioxide that can be produced by that number of moles of octane, based on the mole ratio between octane and carbon dioxide in the balanced equation. Step 3. Then use the ideal gas law to determine the volume in liters of carbon dioxide that can be formed.

5 0

2 years ago

Find the pH of a solution that has an H+ concentration of 2.5x10-3 M

Nastasia [14]

Answer:

The pH is 2, 60

Explanation:

The pH gives us an idea of the acidity or basicity of a solution. It is calculated as:

pH = -log (H +)= -log (2.5x10-3 )

pH=2, 60

7 0

2 years ago

Atoms of elements that are in group 15 with what charge

liq [111]

Answer:

The elements in group 13 and group 15 form a cation with a -3 charge each.

8 0

2 years ago

What volume (in mL) of a 0.200 MHNO3 solution is required to completely react with 27.6 mL of a 0.100 MNa2CO3 solution according

ladessa [460]

Answer:

There is 27.6 mL of a 0.200 M HNO3 solution required

Explanation:

Step 1: The balanced equation is:

Na2CO3(aq)+2HNO3(aq)→2NaNO3(aq)+CO2(g)+H2O(l)

This means for 1 mole Na2CO3 consumed, there is consumed 2 mole of HNO3 and there is produced 2 moles of NaNO3, 1 mole of CO2 and 1 mole of H2O

Step 2: Calculating moles of Na2CO3

moles of Na2CO3 =volume of Na2CO3 * Molarity of Na2CO3

moles of Na2CO3 = 27.6 *10^-3 * 0.1 M = 0.00276 moles

Step 3: Calculating moles of HNO3

In the balanced equation, we can see that for 1 mole of Na2CO3 consumed, there are consumed 2 moles of HNO3.

So for 0.00276 moles consumed of Na2CO3, there are consumed 0.00552 moles of HNO3.

This means 0.00276 moles of the base Na2CO3 would react with 0.00552 moles of the acid HNO3

Step 4: Calculating the volume of HNO3

volume of HNO3 = moles of HNO3 / Molarity of HNO3

volume of HNO3 = 0.00552 moles / 0.200 M = 0.0276 L

0.0276 L = 27.6 ml

There is 27.6 mL of a 0.200 M HNO3 solution required

4 0

2 years ago