Determina el número de moles y moléculas de 25 gr de HCI

The average C - H bond energy in CH4 is 415 kJ / mol. Use the following data to calculate the average C - H bond energy in ethan

sertanlavr [38]

Answer and Explanation:

ΔH = (Bond energies of the products) - (Bond Energies of the reactants)

a) C2H6 + H2 ----> 2CH4 ΔH = -65.07 KJ/mol

Bond energy of product = 2×Bond energy of CH4 =2 × (4 (C-H)) =2 × 4 × 415 = 3320 KJ/mol

Bond energy of reactants = Bond energy of C2H6 + Bond energy of H2

Bond energy of C2H6 = (C-C) + 6(C-H) = 347 + 6(C-H)

Bond energy of H2 = (H-H) = 432 KJ/mol

-65.07 = 3320 - (Bond energy of C2H6 + 432)

Bond energy of C2H6 = 3320-432+65.07 = 2953.07 KJ/mol

Bond energy of C2H6 = (C-C) + 6(C-H) = 347 + 6(C-H) = 2953.07

(C-H) = (2953.07 -347)/6 = 434.345 KJ/mol

b) C2H4 + 2H2 ------> CH4 ΔH = -202.21 KJ/mol

Bond energy of product = 2×Bond energy of CH4 =2 × (4 (C-H)) =2 × 4 × 415 = 3320 KJ/mol

Bond energy of reactants = Bond energy of C2H4 + (2 × Bond energy of H2)

Bond energy of C2H4 = (C=C) + 4(C-H) = 614 + 4(C-H)

(2 × Bond energy of H2) = 2 × 432 = 864 KJ/mol

-202.21 = 3320 - (Bond energy of C2H4 + 864)

Bond energy of C2H4 = 3320+202.21-864 = 2658.1 KJ/mol

Bond energy of C2H4 = (C=C) + 4(C-H) = 614 + 4(C-H) = 2658.1

(C-H) = (2658.1 - 614)/4 = 511.05 KJ/mol

c) C2H2 + 3H2 ------> 2CH4 ΔH = -376.74 KJ/mol

Bond energy of product = 2×Bond energy of CH4 =2 × (4 (C-H)) =2 × 4 × 415 = 3320 KJ/mol

Bond energy of reactants = Bond energy of C2H2 + (3 × Bond energy of H2)

Bond energy of C2H = (triple bond Carbon to Carbon) + 2(C-H) = 839 + 2(C-H)

(3 × Bond energy of H2) = 3 × 432 = 1296 KJ/mol

-376.74 = 3320 - (Bond energy of C2H2 + 1296)

Bond energy of C2H2 = 3320+376.74-1296 = 2400.74 KJ/mol

Bond energy of C2H2 = (triple bond Carbon to Carbon) + 2(C-H) = 839 + 2(C-H) = 2400.74

(C-H) = (2400.74 - 839)/2 = 780.87 KJ/mol

QED!!!

6 0

3 years ago

Another name for light is

Karo-lina-s [1.5K]

Answer:

Another name for light is ¨Electromagnetic Radiation, luminous energy, and/or radiant energy.¨

Explanation:

Light is the electromagnetic radiation that´s capable of causing a visual sensation and has wavelengths from about 380 to about 780 nanometres. Electromagnetic radiation includes Radio Waves, Microwaves (used in microwaves), Infrared Radiation (heat), Visible Light (the colors we see), Ultraviolet (the UV radiation that causes sunburns), X-Rays (used in medical X-Rays), and Gamma Rays (which can be used to treat cancer). Light waves are transverse waves because they only travel east or west, but their crests and troughs face north and south (if desplayed on a coordinate grid). They wouldn´t be longitudinal waves because these waves don´t have vertical crests and troughs.

I hope this helps!

6 0

2 years ago

A 2.04 g lead weight, initially at 10.8 oC, is submerged in 7.74 g of water at 52.2 oC in an insulated container. clead = 0.128

QveST [7]

Answer:

Explanation:

Hello, in this case, the lead is catching heat and the water losing it, that's why the heat relation ship is (D is for Δ):

$DH_{lead}=-DH_{water}$

Now, by stating the heat capacity definition:

$m_{Pb}C_{Pb}*(T_{eq}-T_{lead}=-m_{H_2O}C_{H_2O}*(T_{eq}-T_{H_2O})\\$

Solving for the equilibrium temperature:

$T_{eq}=\frac{m_{Pb}C_{Pb}T_{Pb}+m_{H_2O}C_{H_2O}T_{H_2O}}{m_{Pb}C_{Pb}+m_{H_2O}C_{H_2O}} \\\\T_{eq}=\frac{2.04g*0.128J/(g^oC)*10.8^oC+7.74g*4.18J/(g^oC)*52.2^oC}{2.04g*0.128J/(g^oC)+7.74g*4.18J/(g^oC)} \\\\T_{eq}=51.87^oC$

Which is very close to the water's temperature since the lead's both mass and head capacity are lower than those for water.

Best regards.

5 0

2 years ago

Which of the following is a precipitation reaction? a) Zn (s) + 2 AgNO3 (aq) → 2 Ag (s) + Zn(NO 3) 2 (aq) b) 2 LiI (aq) + Hg 2(N

lawyer [7]

Answer: $2LiI(aq)+Hg_2(NO_3)_2(aq)\rightarrow Hg_2I_2(s)+2LiNO_3(aq)$

Explanation:

A double displacement reaction is one in which exchange of ions take place. The salts which are soluble in water are designated by symbol (aq) and those which are insoluble in water and remain in solid form are represented by (s) after their chemical formulas.

Precipitation is a type of displacement reaction in which one the products is formed in the solid state.

$2LiI(aq)+Hg_2(NO_3)_2(aq)\rightarrow Hg_2I_2(s)+2LiNO_3(aq)$

4 0

2 years ago

PLSSSSSSSS ANSWERRRRR

pav-90 [236]

Your correct! Radio waves I’m pretty sure!

5 0

2 years ago