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2 years ago

Which of the following best defines the internal energy of a system?

1 answer:

7 0

<span>In thermodynamics, the internal energy of a thermodynamic system, or a body with well-defined boundaries, denoted by U, or sometimes E, is the total of the kinetic energy due to the motion of molecules (translational, rotational, vibrational) and the potential energy associated with the vibrational and electric energy of atoms within molecules or crystals. It includes the energy in all the chemical bonds, and the energy of the free, conduction electrons in metals.</span>

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Aluminum reacts with sulfur gas to produce aluminum sulfide

weqwewe [10]

Answer:

What is the question? It looks like a fact.

Explanation:

4 0

3 years ago

The following substances dissolve when added to water. Classify the substances according to the strongest solute-solvent interac

Norma-Jean [14]

Answer:

CuCl2-Ion-dipole forces

CuSO4-Ion-dipole forces

NH3-Dipole-dipole forces

CH3OH-Dipole-dipole forces

Explanation:

Water consists of a dipole. The water molecule contains a positive end and a negative end. The positive ion attracts the negative dipole of water while the positive dipole in water interacts with the negative ion of an ionic substance. This explains the dissolution of ionic substances in water.

Copper II chloride and copper sulphate are ionic substances hence they dissolve by the mechanism described above.

Molecules consisting of dipoles dissolves by interaction of the molecule's dipoles with the dipoles in water. For example, methanol interacts with water through hydrogen bonding which is involves molecular dipoles

3 0

2 years ago

What is the Ka of a weak acid (HA) if the initial concentration of weak acid is 4.5 x 10-4 M and the pH is 6.87? (pick one)

rewona [7]

Answer:

Ka = $4.04 \times 10^{-11}$

Explanation:

Initial concentration of weak acid = $4.5 \times 10^{-4}\ M$

pH = 6.87

$pH = -log[H^+]$

$[H^+]=10^{-pH}$

$[H^+]=10^{-6.87}=1.35 \times 10^{-7}\ M$

HA dissociated as:

$HA \leftrightharpoons H^+ + A^{-}$

(0.00045 - x) x x

[HA] at equilibrium = (0.00045 - x) M

x = $1.35 \times 10^{-7}\ M$

$Ka = \frac{[H^+][A^{-}]}{[HA]}$

$Ka = \frac{(1.35 \times 10^{-7})^2}{0.00045 - 0.000000135}$

0.000000135 <<< 0.00045

$Therefore, Ka = \frac{(1.35 \times 10^{-7})^2}{0.00045 } = 4.04 \times 10^{-11}$

5 0

2 years ago

Which element would have the lowest electronegativity? (1 point)

lutik1710 [3]

The element which would have the lowest electronegativity is: an element with a small number of valence electrons and a large atomic radius.

Atomic radii can be defined as a measure of the size (distance) of the atom of a chemical element such as hydrogen, oxygen, carbon, nitrogen etc, typically from the nucleus to the valence electrons. The atomic radius of a chemical element decreases across the periodic table, typically from alkali metals (group one elements such as hydrogen, lithium and sodium) to noble gases (group eight elements such as argon, helium and neon). Also, the atomic radius of a chemical element increases down each group of the periodic table, typically from top to bottom (column).

Generally, atoms with relatively large atomic radii tend to have a low electronegativity, ionization energy and a low electron affinity.

Valence electrons can be defined as the number of electrons present in the outermost shell of an atom. Thus, number of valence electrons is typically used to determine the chemical properties of elements such as electronegativity.

Electronegativity can be defined as the ability or tendency of the atom of an chemical element to attract any shared pair of electrons.

In conclusion, a chemical element that has small number of valence electrons and a large atomic radius would have the lowest electronegativity.

Find more information: brainly.com/question/24370190

8 0

3 years ago

As the ph ________, the concentration of hydrogen ions increases, and the solution becomes ____________.

Sauron [17]

As the ph Decreases, the concentration of hydrogen ions increases,and the solution becomes acidic.

5 0

2 years ago