What is the pH of an aqueous solution of HCl with a hydrogen ion

When the oxide of generic metal m is heated at 25.0 °c, only a negligible amount of m is produced. o2m(s ----> m(s o2(g delta

Len [333]

(1) MO₂(s) + C(s) → M(s) + CO₂ (g), ΔG₁ = 288.9 kJ/mol
(2) C(s) + O₂(g) → CO₂(g), ΔG₂ = -394.4 kJ/mol
By adding both equations 1 + 2 we get the coupled reaction:
MO₂(s) + 2 C(s) + O₂(g) → M(s) + 2 CO₂(g)
ΔG⁰ = ΔG₁ + ΔG₂
= 288.9 + (-394.4) = -105.5 kJ/mol = -105500 J/mol
Temperature T = 25 + 273.15 = 298.15 K
Molar gas constant R = 8.314 J/mol.K
K = $e^{ \frac{-dG0}{RT} }$
= $e^{ \frac{105500}{8.314 x 298.15} }$
= 3.05 x 10¹⁸

6 0

3 years ago

A. How many moles of H2 are produced from two<br> moles of CH4 ?

Nina [5.8K]

Every mole of CH4 used, three moles of H2 are produced, so 2 moles of CH4, would be 6 moles of H2 produced

8 0

2 years ago

13. What is the symbol for Enthalpy change?

OverLord2011 [107]

Answer:

Explanation:

13 ) symbol of enthalpy change = Δ H .

14 ) enthalpy change is nothing but heat absorbed or evolved .

During fusion enthalpy change

Δ H .= m Lf , m is mass and Ls is latent heat of fusion

During evaporation, enthalpy change

Δ H .= m Lv , m is mass and Lv is latent heat of evaporation

during temperature rise , enthalpy change

Δ H = m c Δ T

In case of gas , enthalpy change can be calculated by the following relation

Δ H = Δ E + W , Δ E is change in internal energy , W is work done by gas.

15 ) When enthalpy change is negative , that means heat is released to the environment .So reaction is called exothermic .

when heat is absorbed enthalpy change is positive . Reaction is endothermic.

5 0

3 years ago

Consider the reaction below for which K = 78.2 atm-1. A(g) + B(g) ↔ C(g) Assume that 0.386 mol C(g) is placed in the cylinder re

borishaifa [10]

Answer:

1.65 L

Explanation:

The equation for the reaction is given as:

A + B ⇄ C

where;

numbers of moles = 0.386 mol C (g)

Volume = 7.29 L

Molar concentration of C = $\frac{0.386}{7.29}$

= 0.053 M

A + B ⇄ C

Initial 0 0 0.530

Change +x +x - x

Equilibrium x x (0.0530 - x)

$K = \frac{[C]}{[A][B]}$

where

K is given as ; 78.2 atm-1.

So, we have:

$78.2=\frac{[0.0530-x]}{[x][x]}$

$78.2= \frac{(0.0530-x)}{(x^2)}$

$78.2x^2= 0.0530-x$

$78.2x^2+x-0.0530=0$

Using quadratic formula;

$\frac{-b+/-\sqrt{b^2-4ac} }{2a}$

where; a = 78.2 ; b = 1 ; c= - 0.0530

= $\frac{-b+\sqrt{b^2-4ac} }{2a}$ or $\frac{-b-\sqrt{b^2-4ac} }{2a}$

= $\frac{-(1)+\sqrt{(1)^2-4(78.2)(-0.0530)} }{2(78.2)}$ or $\frac{-(1)-\sqrt{(1)^2-4(78.2)(-0.0530)} }{2(78.2)}$

= 0.0204 or -0.0332

Going by the positive value; we have:

x = 0.0204

[A] = 0.0204

[B] = 0.0204

[C] = 0.0530 - x

= 0.0530 - 0.0204

= 0.0326

Total number of moles at equilibrium = 0.0204 + 0.0204 + 0.0326

= 0.0734

Finally, we can calculate the volume of the cylinder at equilibrium using the ideal gas; PV =nRT

if we make V the subject of the formula; we have:

$V = \frac{nRT}{P}$

where;

P (pressure) = 1 atm

n (number of moles) = 0.0734 mole

R (rate constant) = 0.0821 L-atm/mol-K

T = 273.15 K (fixed constant temperature )

V (volume) = ???

$V=\frac{(0.0734*0.0821*273.15)}{(1.00)}$

V = 1.64604

V ≅ 1.65 L

3 0

3 years ago

Magnesium has three naturally occurring isotopes with masses of 23.99 amu, 24.99 amu, and 25.98 amu and natural abundances of 78

mihalych1998 [28]

Answer:24.31

Explanation:Contribution made by isotope of mass 23.99= 23.99×78.99=1894.97

Contribution made by isotope of mass 24.99=24.99×10.00=249.9

Contribution made by isotope of mass 25.98=25.98×11.01=286.04

Total contribution=1894.97+249.9+286.04=2430.91

Average mass=2430.91÷100

=24.31

3 0

3 years ago