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3 years ago

I need help help me please

Chemistry

1 answer:

Rzqust [24]3 years ago

3 0

Answer:

C is the correct answer.

Explanation:

We can eliminate some answers immediately:

A is incorrect because nitrogen and hydrogen do not change their identity, they just combine into a new molecule that contains them. Notice how there are 2 nitrogen atoms and 6 hydrogen atoms on both sides of the equation.

B is incorrect because the first law of thermodynamics tells us that matter and energy will always be conserved, so the mass of the products must be equal to the mass of the reactants, not less than the mass of the reactants.

C is correct because balanced chemical equations help chemists predict how much product will form from certain amounts of reactants.

D is incorrect because this equation is showing the exact opposite. Molecular hydrogen and nitrogen can combine stoichiometrically to form ammonia.

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if the spin of one electron in an orbital is clockwise , what is the spin of the other electron in that orbital

nata0808 [166]

Here we have to get the spin of the other electron present in a orbital which already have an electron which has clockwise spin.

The electron will have anti-clockwise notation.

We know from the Pauli exclusion principle, no two electrons in an atom can have all the four quantum numbers i.e. principal quantum number (n), azimuthal quantum number (l), magnetic quantum number (m) and spin quantum number (s) same. The importance of the principle also restrict the possible number of electrons may be present in a particular orbital.

Let assume for an 1s orbital the possible values of four quantum numbers are n = 1, l = 0, m = 0 and s = $\frac{+}{-}$ $\frac{1}{2}$ .

The exclusion principle at once tells us that there may be only two unique sets of these quantum numbers:

1, 0, 0, + $\frac{1}{2}$ and 1, 0, 0, - $\frac{1}{2}$ .

Thus if one electron in an orbital has clockwise spin the other electron will must be have anti-clockwise spin.

6 0

3 years ago

The orbit of a planet is an ellipse with the sunat one of the foci.. This is Kepler's........ second law third law first law

Svetradugi [14.3K]

Answer:

its keplers first law

Explanation:

answer from gauth math

6 0

3 years ago

Which of the following describe chemical properties

alexandr1967 [171]

Chemical properties are all those properties that are shown when the chemical is a part of a reaction or is changed in any way. Unlike physical properties, they affect the composition of the chemical and the way it behaves, while physical does not change the chemical itself. Such properties are toxicity, flammability, reaction with other elements, stability, and many more.

3 0

3 years ago

Write a balanced equation and determine Eº for each of the following cells: a) Cr Cr3+||Ni2+|Ni b) (CF|C1,||MnO | Mn?)

Alexxx [7]

Answer:

Explanation:

Step 1: Write both half reactions

Cr / Cr3+ : oxidation Cr(s) → Cr3+ + 3e-

Ni2+ / Ni : reduction Ni2+ +2e- → Ni

Step 2: Balance reactions and look up the standard potential for the half-reactions

2(Cr → Cr3+ + 3e-) E° ox = 0.74 V

3(Ni2+ +2e- → Ni) E° red = -0.25 V

2Cr + 3Ni2+ +6e- → 2Cr3+ +6e- + 3Ni

E°cell = E° red + E° ox = -0.25 + 0.74 = 0.49

E = E ° − 0.0257 V /n * ln Q = E ° − 0.0257 V /n *l n [ C r 3 + ]/ [ N i 2 + ]

With E° = 0.49 V

Step 1: Write both half reactions

MnO4-/ Mn2+ (redution) MnO4- +8H+ +5e- ⇔ Mn2+ +4H2O

Cf ⇔ Cf2+ +2e- (oxidation) Cf ⇔ Cf2+ +2e-

Step 2: Balance reactions and look up the standard potential for the half-reactions

MnO4- +8H+ +10-e- ⇔ Mn2+ +4H2O E° = 1.51 V

5Cf ⇔ 5 Cf2+ +10e- E° =2.12 V

2 MnO4- + 16H+ + 5Cf ⇔ 2Mn2+ + 8H2O + 5Cf2+

E°cell = E° red + E° ox = 1.51 + 2.12 = 3.63 V

E = E ° − 0.0257 V /n * ln Q = E ° − 0.0257 V /n *l n [ C f2 + ]/ [ Mno4- ]

With E° =3.63 V

7 0

3 years ago

(b) Once the ionic solid has dissolved, the anion that is formed is able to react as a base, with water as the acid. Write the n

Marrrta [24]

Answer:

b C₂H₃O₂⁻ + H₂O ⇄ HC₂H₃O₂ + OH⁻

e HC₂H₃O₂ + H₂O ⇄ H₃O⁺ + C₂H₃O₂⁻

f ka<<1

g. Weak acid molecules and water molecules

Explanation:

The water molecule could act as a base and as an acid, a molecule that have this property is called as amphoteric.

b The salt NaC₂H₃O₂ is dissolved in water as Na⁺ and C₂H₃O₂⁻. The reaction of the anion with water is:

C₂H₃O₂⁻ + H₂O ⇄ HC₂H₃O₂ + OH⁻

Where the C₂H₃O₂⁻ is the base and water is the acid.

e. The reaction of HC₂H₃O₂ (acid) with water (base), produce:

HC₂H₃O₂ + H₂O ⇄ H₃O⁺ + C₂H₃O₂⁻

f. As the acetic acid (HC₂H₃O₂) is a week acid, the dissociation in C₂H₃O₂⁻ is not complete, that means that ka<<1

g. The ka for this reaction is 1,8x10⁻⁵, that means that there are more weak acid molecules (HC₂H₃O₂) than conjugate base ions. Also, the water molecules will be in higher proportion than hydronium ions.

I hope it helps!

4 0

3 years ago