What is an experiment that can verify that new substances are formed and heat is released or absorbed during a chemcal reaction?

A methanol-water mixture is to be flash distilled at 1 atm. If the feed is 25 mole %methanol, what are the liquid and vapor comp

frozen [14]

Answer:

Explanation:

Given that:

The distillation is carried out at a pressure of 1 atm

The feed harbors 25% mole of methanol (z)

The total moles of feed is usually 100 moles

In the system, we have both methanol and water

Using the total mole balance for the distillation column.

Fz = Lx + Vy

where;

F = amount of feed

z = mole fraction of ethanol (in feed)

L = amount of liquid product out of the column

V = amount of vapor product out of the column

x = mole fraction of methanol out of the liquid

y = mole fraction of methanol out of the vapor.

SO;

(a)

If all the feed is vaporized, then the vapor will likely have the same composition as the feed.

(b)

If no vaporization of the feed takes place, then the bottoms moving out of the column contains the same composition as the feed.

(c)

If 1/3 of the feed is vaporized; then 2/3 of the feed is at the bottom.

The balance equation would be:

$Fz = (\dfrac{2}{3}F) x + (\dfrac{1}{3}F)y \\ \\ z = \dfrac{2}{3}x+\dfrac{1}{3}y$

Replacing z = 0.25; we have:

$0.25 = \dfrac{2}{3}x+\dfrac{1}{3}y$

0.75 = 2x + y

(d)

If 2/3 of the feed is vaporized;

Then:

$Fz = (\dfrac{1}{3}F) x + (\dfrac{2}{3}F)y \\ \\ z = \dfrac{1}{3}x+\dfrac{2}{3}y$

replacing z = 0.25

$0.25 = \dfrac{1}{3}x+\dfrac{2}{3}y$

0.75 = x + 2y

6 0

3 years ago

14. I have an unknown volume of gas at a pressure of 1.2 atm and a temperature of 210 K. If I raise the pressure to 1.9 atm and

Leya [2.2K]

Answer:

The law is given by the following equation: PV = nRT, where P = pressure, V = volume, n = number of moles, R is the universal gas constant, which equals 0.0821 L-atm / mole-K, and T is the temperature in Kelvin.

Explanation:

6 0

3 years ago

An acidic fog in pasadena was found to have a ph of 2.50. which expression represents this ph measurement?

joja [24]

Supposing a temperature of 25 degrees and supposing that all activity coefficients are 1

pH = -log[H+]
pOH = -log[OH-]
pH + pOH = 14

Thus a pH of 2.50 would mean that the [H+], the concentration of the hydrogen ion, would be 10^(-2.50)

pH + pOH = 14
pOH = 14 - pH = 14 - 2.5 = 11.5
MOH- levels would be coordinated with pOH
pOH = -log[OH-] ==> [OH-] = [MOH-] = 10^-pOH = 10^-11.5 = 3.2 x 10^-12

Therefore, MOH¯ = 3.2 × 10¯12 M

5 0

3 years ago

How do non contact forces affect the world around us

dolphi86 [110]

A Non Contact Force is a force which acts on an object without coming physically in contact with it.[1] The most familiar example of a non-contact force is gravity, which confers weight.[1] In contrast a contact force is a force applied to a body by another body that is in contact with it.[1]

3 0

3 years ago

According to bond energy tables, the triple bond of N2 is 946 kJ/mol while the bond of I2 is 151 kJ/mol. Based on simple chemica

Dmitry_Shevchenko [17]

Answer:

Yes, in both cases the reactant bond must be broken before the H can bond.

Explanation:

Let us remind ourselves of the basics of the collision theory. According to this theory, chemical reaction occurs because of the collision of particles of substances in a chemical reaction system.

This means that the bond between reactants must first be broken and new bonds formed in products. Activation energy is the minimum energy required for a reaction to occur. This energy goes into the rearrangement of reactant bonds to enable them to recombine and form products.

Since the N2 bond energy is far higher than the I2 bond energy, a greater degree of energy is needed overcome the energy barrier in the reaction of H2 with N2 compared to the reaction of H2 and I2 . Therefore, the activation energy for the reaction of H2 and N2 is much higher than the activation energy for the reaction of H2 with I2.

4 0

3 years ago