Estimate ΔG°rxn for the following reaction at 449.0 K. CH2O(g) + 2 H2(g) → CH4(g) + H2O(g) ΔH°= -94.9 kJ; ΔS°= -224.2 J/K

Answer: The right choice is (c) application of both a mobile phase and a stationary phase.

Explanation:

Chromatography: This refers to a technique for separating a mixture where the mixture is distributed between two phases at varying rates, one being stationary and the other moving.

Mobile phase: The component in which the mixture is dissolved is referred to as the mobile phase.

Stationary phase: This is an adsorbent medium that remains in place while a liquid or gas passes over its surface, thus remaining stationary.

Consequently, a key characteristic of any chromatography technique involves utilizing both a mobile and a stationary phase.

Answer:

The molality is 1.15 m.

Molality is calculated by dividing the number of moles of solute by the kilograms of solvent, which in this case is water.

Calculate moles of H₂SO₄ from molarity:

C = n/V → n = C × V = 6.00 mol/L × 0.048 L = 0.288 moles

Mass of solvent (water) based on density:

m = ρ × V = 1.00 kg/L × 0.250 L = 0.250 kg

Therefore, molality is:

m = moles/solvent mass = 0.288 moles / 0.250 kg = 1.15 m

Moving on to the second issue

Let's tackle the second question first. Once you grasp that, the first question will be simpler. By the way, this is an excellent question to clarify. The concepts of less than and more than can be quite tricky in the sciences. Every question you encounter that utilizes less or more should be approached with caution.

As altitude increases, air pressure decreases (essential term: less highlight this sentence in color. Take a moment to reflect on it.)

As the pressure declines, less energy (again, key term) is required for water molecules to escape the surface. Thus, the boiling temperature is lower than it would be at sea level.

Answer to problem two: Lower

Problem One

Water reaches its boiling point when the greatest number of molecules can leave the water's surface. Equal to is the right answer.  Although pinpointing the exact answer can be challenging, equal to is indeed the correct response.

The balanced chemical equation for the neutralization of HCl with is:

Given weight of = 5g

Moles of =

Volume of HCl solution =

Assuming the density of the solution is 1.0 g/mL

Mass of HCl solution = 50 g

Overall mass of the solution = 50 g + 5 g = 55 g

To find the heat of neutralization, we calculate:

Q = m C ΔT

where m equals the mass of the solution = 55 g

C represents the specific heat capacity of the solution = 4.184

ΔT signifies the temperature change = 6.8 K = (6.8 - 273) C = -266.2

The enthalpy of neutralization per mole of

=

Result: The count of bonding electrons and non-bonding electrons amounts to (4, 18).

Explanation:

The Lewis-dot structure reveals the number of bonding and non-bonding electrons in .

Lewis-dot representation: It illustrates the valence electron count for atoms in a molecule and shows how they bond, as well as any lone pairs of electrons.

In this structure, 'Xe' is the central atom while 'F' is the terminal atom.

Xenon comprises 8 valence electrons, whereas fluorine contains 7.

The total number of valence electrons in is calculated as 8 + 2(7) = 22 electrons

From the Lewis-dot structure, we can determine

The count of electrons involved in bonding = 4

The count of electrons involved in non-bonding (lone-pairs) = 22 - 4 = 18

Thus, the bonding and non-bonding electron counts are (4, 18).

Below is the Lewis-dot structure for .