What is the mass or 1.53 x 10^23 molecules of H2SO4?

Consider the reactionI2(g) + Cl2(g)2ICl(g)Using standard thermodynamic data at 298K, calculate the entropy change for the surrou

Georgia [21]

We know,

$\Delta H_{I_2(g)}=62.438\ KJ/mol\\\\\Delta H_{Cl_2(g)}= 0.0\ KJ/mol\\\\\Delta H_{ICl(g)}=17.78\ KJ/mol$

For given reaction, $I_2(g)+Cl_2(g)\ -->\ 2ICl(g)$

$\Delta H_{rxn}=2\Delta H_{ICl(g)}-\Delta H_{I_2(g)}-\Delta H_{Cl_2(g)}\\\\\Delta H_{rxn}=2(17.78)-0-62.438\ KJ/mol\\\\\Delta H_{rxn}=-26.878\ KJ/mol$

For , 2.41 moles of $I_2$ :

$\Delta H_{rxn}=2.41\times (-26.878)\ KJ\\\\\Delta H_{rxn}=-64.78\ KJ$

We know :

$\Delta S = -\dfrac{\Delta H_{rxn}}{T}\\\\\Delta S = -\dfrac{-64.78}{298}\ KJ/K\\\\\Delta S =-0.21738 \ KJ/K\\\\\Delta S=-217.38\ J/K$

Hence, this is the required solution.

7 0

3 years ago

Quinine is an important type of molecule that is involved in photosynthesis. The transport of electrons mediated by quinone in c

Irina18 [472]

Answer:

The heat of combustion is -25 kJ/g = -2700 kJ/mol.

Explanation:

According to the Law of conservation of energy, the sum of the heat released by the combustion reaction and the heat absorbed by the bomb calorimeter is equal to zero.

Qcomb + Qcal = 0

Qcomb = - Qcal

The heat absorbed by the calorimeter can be calculated with the following expression.

Qcal = C × ΔT

where,

C is the heat capacity of the calorimeter

ΔT is the change in temperature

Then,

Qcomb = - Qcal

Qcomb = - C × ΔT

Qcomb = - 1.56 kJ/°C × 3.2°C = -5.0 kJ

Since this is the heat released when 0.1964 g o quinone burns, the energy of combustion per gram is:

$\frac{-5.0kJ}{0.1964g} =-25kJ/g$

The molar mass of quinone (C₆H₄O₂) is 108 g/mol. Then, the energy of combustion per mole is:

$\frac{-25kJ}{g} .\frac{108g}{1mol} =-2700kJ/mol$

6 0

3 years ago

How many valence electrons does B (boron) have? A. 13 B. 5 C. 10 D. 3

pshichka [43]

Answer:

Boron has 3 valence electrons

8 0

3 years ago

Name the following alkyne. Please help me <3

Alexandra [31]

Answer:

D. 7-methyl-3-octyne

Explanation:

1) Identify the parent chain and name it like an alkane.

• The longest chain of carbons, which consists of the functional group (which is the alkyne group in this case: C≡C).

• There are 8 carbons in the longest chain, so it is called an octane.

2) Now, identify the location of the functional group.

• The location number of the functional group should be as low as possible. Thus although we could count from the right, we start counting from the left since the functional group is closer to the left. From the left, the functional group would be at carbon 8 while from the left, it is on carbon 3.

• Replace 'ane' with 'yne' in octane for the alkyne group.

• This would give us 3-octyne.

3) Lastly, add in the name of the branch.

• Here we have one branch, -CH₃. This is read as methyl.

• Identify the location number of the branch by counting the number of carbons in the same direction as when we counted the location number of the functional group. The methyl branch has a location number of 7.

• Adding the name of the branch before the parent chain, we would arrive at 7-methyl-3-octyne as the IUPAC name of the alkyne.

Further Explanation:

A) This option is incorrect as there are only 8 carbons in the parent chain. Although there are 9 carbons in total, the 9th carbon is taken care of in '7-methyl'.

B) Location number of the functional group should be as low as possible, so start counting the number of carbons from the left!

C) Since the functional group is an alkyne, the word 'octane' should be 'octyne' instead.

8 0

3 years ago

1. A cold front forms when-

Aleks [24]

A cold air mass moves into an area of warm air

4 0

3 years ago