Chemistry-mole calculations

A hydrogen-like ion is an ion containing only one electron. The energies of the electron in a hydrogen-like ion are given by the

yan [13]

Answer:

The ionization energy (in kJ/mol) of the helium ion is 21,004.73 kJ/mol .

Explanation:

$E_n = -(2.18 10-18 J)\times \frac{Z^2}{n^2}$

Z = atomic mass

n = principal quantum number

Energy of the electron in n=1,

$E_1= -(2.18 10^{-18} J)\times \frac{4^2}{1^2}=-3.488\times 10^{-17} J$

Energy of the electron in n = ∞

$E_{\infty}= -(2.18 10^{-18} J)\times \frac{2^2}{\infty ^2}=0 J$

Ionization energy of the $He^+$ ion:

$I.E=E_{infty}-E_1=0-(-3.488\times 10^{-17} J)=3.488\times 10^{-17} J$

$I.E=3.488\times 10^{-20} kJ$

To convert in into kj/mol multiply it with $N_A=6.022\times 10^{23} mol^{-1}$

$I.E=3.488\times 10^{-20} kJ\times 6.022\times 10^{23} mol^{-1}=21,004.73kJ/mol$

3 0

3 years ago

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The mass of 0.10 mole of methane

saveliy_v [14]

Answer:

A methane molecule is made from one carbon atom and four hydrogen atoms. Carbon has a mass of 12.011 u and hydrogen has a mass of 1.008 u. This means that the mass of one methane molecule is 12.011 u + (4 × 1.008u), or 16.043 u. This means that one mole of methane has a mass of 16.043 grams.

メタン分子は、1つの炭素原子と4つの水素原子から作られています。炭素の質量は12.011uで、水素の質量は1.008uです。これは、1つのメタン分子の質量が12.011 u +（4×1.008u）、つまり16.043uであることを意味します。これは、1モルのメタンの質量が16.043グラムであることを意味します。^>^

5 0

3 years ago

Zinc will displace copper from a solution of copper sulfate, and magnesium will displace zinc from a solution of zinc sulfate. W

Anna [14]

Answer:

The displacement reactions are regarded as redox reactions because they involve the formal transfer of electrons from one chemical specie to the other

2) The series of reactivity of the metals in the order of increasing reactivity are;

Copper

↓

Zinc

↓

Magnesium

Explanation:

1) Redox (oxidation-reduction) reaction is a chemical reaction involving the loss and gain of electrons from one chemical species to another, where the chemical species that undergoes oxidation, loses electrons and is termed the reducing agent, while the other chemical species that undergoes reduction, gains electrons, and is termed the oxidizing agent

2) The redox reaction can being based on the affinity for electrons depends on the positions of the reactants in the electrochemical series as well as the chemical reactivity of the metals with zinc being a stronger reducing agent and more chemically reactive than copper and magnesium being a stronger reducing agent and more chemically reactive than zinc

Least reactive (Cu) < (Zn) < Mg Most reactive

Copper < Zinc < Magnesium.

4 0

3 years ago

In a chemical reaction, the difference between the potential energy of the products of the potential energy of the reactants is

Svetradugi [14.3K]

Your question looks a bit incomplete as you have the same contents in options a) and d). According to your list, I can't see the correct answer, but I can give you one.The difference between the potential energy of the products of the potential energy of the reactants is equal to the enthalpy of the reaction.

7 0

3 years ago

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Which has the larger radius, F or F− ?

vlabodo [156]

Answer is B- F has a smaller radius than F− because an additional electron causes greater repulsion in F− is the correct choice and the nuclear charge the radius of the anion increases.

Explanation: I hoped that helped!

6 0

3 years ago