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3 years ago

How would you calculate the difference in enthalpy?

1 answer:

7 0

(Biology)
Equation: (delta)G = (delta)H - T (delta)S
(delta)G stand for change in free energy. When it is positive, it is endergonic. When it is negative, it is exergonic.
H stands for bond energy and is enthalpy
T is the absolute temperature expressed in the Kelvin scale
S is entropy or disorder in the system

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A neutral atom posseses an atomic number of 15 and an atomic mass of 31 3 electrons are gained

kodGreya [7K]

Answer:I believe the correct answer from the choices listed above is option D. A

Explanation:neutral atom possesses an atomic number of 15 and an atomic mass of 31.Three electrons are gained. This conversion results to a negatively charged ion.

8 0

3 years ago

Which of the following was not a contribution by Niels Bohr?Electrons are in orbits. There is a relationship between the outer s

lara31 [8.8K]

Neil Bohr contributed towards science in many ways, but his contributions did not include the charge of an electron. Neil Bohr recognized a relationship between the chemical properties of a substance and the number of valence shell electrons. Moreover, he introduced the atomic model in 1913 and provided the liquid-drop model to explain nuclear fusion.

6 0

3 years ago

Read 2 more answers

Phosphorus can be stable with 12 electrons in its valence structure while nitrogen can never have more than 8 electrons in its v

dolphi86 [110]

Here we have explain that the maximum possible electrons present in nitrogen valence shell is 8 whereas in phosphorous 12 valence electrons are present.

Although both nitrogen (N) and phosphorous (P) belongs to the same series there are several properties which are different between both the element. The number of electrons present in nitrogen is seven which are present in the -s and -p orbitals. The electronic configuration of nitrogen is 1s²2s²2p³. In which the outermost electrons are the valence electrons i.e. 5 valence electrons are present. The maximum orbitals are possible under the principal quantum number 2 are -s and -p orbitals. Now the maximum capacity of the p orbital to contain 6 electrons, as it is half filled in nitrogen another 3 electrons can be incorporated. Thus the maximum number of electrons can be present in nitrogen is 10 among which 8 is the valence electrons.

On the other hand there are 15 electrons in phosphorous the electronic configuration is 1s²2s²2p⁶3s²3p³. Now the principal quantum number 3 can have three orbitals -s, -p and -d. So another 13 electrons can be incorporated (3 in -p orbital and 10 in -d orbital) among which upto 12 electrons can be its valence electrons.

8 0

3 years ago

A gas mixture contains 0.700 mol of N2, 0.300 mol of H2, and 0.400 mol of CH4. Calculate the pressure of the gas mixture and the

Nitella [24]

Answer:

Pressure of the gas mixture: 4.30 atm

Partial pressure N₂ = 2.15 atm

Partial pressure H₂ = 0.91 atm

Partial pressure CH₄ = 1.23 atm

Explanation:

To determine partial pressure we sum the total moles in order to find out the total pressure

We can work with mole fraction

We apply the Ideal Gases Law

0.700 N₂ + 0.300 H₂ + 0.400 CH₄ = 1.4 moles

We replace data → P . V = n . R .T

T° must be at K → 27 °C + 273 = 300 K

P . 8 L = 1.4 mol . 0.082 L.atm/mol.K . 300 K

P = ( 1.4 mol . 0.082 L.atm/mol.K . 300 K) / 8 L = 4.30 atm (Total pressure)

We apply the mol the fraction for the partial pressure

Moles x gas / total moles = partial pressure x gas / total pressure

Mole fraction N₂ → 0.700 /1.4 = 0.5

Partial pressure N₂ = 0.5 . 4.30 atm =2.15 atm

Mole fraction H₂ → 0.300 / 1.4 = 0.21

Partial pressure H₂ = 0.21 . 4.30 atm = 0.91 atm

Mole fraction CH₄ → 0.400 /1.4 = 0.28

Partial pressure CH₄ = 0.28 . 4.30 atm =1.23 atm

7 0

3 years ago

Read 2 more answers

What mass of chromium would be produced from the reaction of 57.0 g of potassium with 199 g of chromium(II) bromide according to

fredd [130]

Answer:

Mass of Chromium produced = 37.91 grams

Explanation:

2K + CrBr₂ → 2KBr + Cr

2mole 1 mole 1 mole

mass of Potassium = 57.0 grams

molar mass of Potassium = 39.1 g/mol

no of moles of Potassium = 57.0 / 39.1 = 1.458 moles

mass of CrBr₂= 199 grams

molar mass of CrBr₂ = 211.8 gram/mole

no of moles of CrBr₂ = 199 / 211.8 = 0.939 mole

From chemical equation

1 mole of CrBr₂ = 2 moles of K

∴ 0.939 moles of CrBr₂ = ?

⇒ 0.939 x 2/1 = 1.878 moles of K

1.878 moles of K is needed, but there is 1.458 moles of K. So, Potassium is completed first during the reaction . Hence, Potassium is limiting reagent. and CrBr₂ is excess reagent .

From chemical equation

2 moles of K = 1 mole of Cr

∴ 1.458 moles of K = ?

⇒ 1.458 x 1/ 2 = 0.729 moles of Cr

no of moles of Cr formed = 0.729 moles

molar mass of Cr = 52.0 g/mol

mass of one mole of Cr = 52.0 grams

mass of 0.729 moles of Cr = 52.0 x 0.729 = 37.908 grams

mass of Chromium produced = 37.91 grams

6 0

3 years ago