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3 years ago

Hydrogen can be prepared on a small scale by the hydrolysis of metal hydrides:

Chemistry

1 answer:

lara [203]3 years ago

6 0

Answer:

Ca²⁺ + 2H⁻ + 2(2H⁺ + O²⁻) ----> Ca²⁺ + 2O²⁻ + 2H⁺ + 4H⁰

(2 electrons lost) ----> (2 electrons gained)

Explanation:

The equation of the reaction is as follows: CaH₂ + 2H₂0 —> Ca(OH)₂ + 2H₂

The oxidation numbers of each of the atoms in the molecules are as follows:

In CaH₂, calcium has an oxidation number of +2, while hydrogen has an oxidation number of -1 ; Ca²⁺, 2H⁻

In 2H₂0, hydrogen has an oxidation number of +1 while oxygen has an oxidation number of -2 ; H⁺, O²⁻

In Ca(OH)₂, calcium has an oxidation number of +2 while oxygen has an oxidation number of -2 and hydrogen has an oxidation number of +1 ; Ca²⁺, O²⁻, 2H⁺

In 2H₂, each hydrogen atom has an oxidation number of 0 ; 4 H⁰

Ca²⁺ + 2H⁻ + 2(2H⁺ + O²⁻) ----> Ca²⁺ + 2O²⁻ + 2H⁺ + 4H⁰

On the left hand side, the hydride ion gives up two electrons to become neutral hydrogen atoms.

On the right hand, two hydrogen atoms accept two electrons to form neutral atoms.

These neutral hydrogen atoms pair up to form two hydrogen gas molecules.

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Pani-rosa [81]

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3 years ago

P4+ __02_ P4010 I need help ASAP

klasskru [66]

Answer:

$P_4+5O_2\rightarrow P_4O_{10}$

Explanation:

Hello!

In this case, when we want to balance chemical reactions such as in this case, the idea is to equal to number of atoms of each element at each side of the equation according to the lay of conservation of mass, just as shown below:

$P_4+5O_2\rightarrow P_4O_{10}$

Because we have four phosphorous and ten oxygen atoms at each side.

Best regards!

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2 years ago

What are the trends for atomic size and ionization? Explain why for each trend. Tell me the direction- up or down a group and ac

Alinara [238K]

Answer:

See explanation

Explanation:

Atomic size increases down the group due to the addition of more shells.

As more shells are added and repulsion of inner electrons become more significant, atomic size increases down the group. However, across the period, atomic size decreases due to increase in effective nuclear charge without any increase in the number of shells. This causes increased attraction between the nucleus and the outermost shell thereby decreasing the size of the atom.

Ionization energy decreases down the group because the outermost electron is more shielded by inner electrons making it easier for this outermost electron to be lost. Across the period, ionization energy increases due to increase in effective nuclear charge which makes it more difficult to remove the outermost electron due to increased nuclear attraction.

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3 years ago

What is the bond between Ca and Cl

gtnhenbr [62]

ionic bond is formed between ca and cl forming molecule cacl2 ca has 2 velancy and cl has one velancy (ca has 2 electrons in its outer most shell while cl has 1 electron vecancy in its outermost shell). So ca would make bond with 2 cl atoms

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3 years ago

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Alex777 [14]

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2 years ago