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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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The four sets of lines in the hydrogen emission spectrum are known as Balmer, Brackett, Paschen, and Lyman. For each series, ass

arlik [135]

Answer:

Hydrogen spectrum

Explanation:

Balmer series - Observed in the visible region

Brackett series - Observed in the infrared region

Paschen series - Observed in the infrared region

Lyman series - Observe in the Ultraviolet region.

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3 years ago

Identify a cation. An atom that has gained a proton. An atom that has lost an electron. An atom that has gained an electron. An

iren2701 [21]

the answer would be B an atom that has lost an electron

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2 years ago

What is the volume (in liters) occupied by 49.8 g og HCl at STP

Anon25 [30]

Using ideal gas equation,

P\times V=n\times R\times T

Here,

P denotes pressure

V denotes volume

n denotes number of moles of gas

R denotes gas constant

T denotes temperature

The values at STP will be:

P=1 atm

T=273 K

R=0.0821 atm L mol ⁻¹

Mass of HCl given= 49.8 g

Molar mass of HCl given=36.41

Number of moles of gas, n= \frac{Given mass of the substance}{Molar mass of the substance}

Number of moles of gas, n= \frac{49.8}{36.46}

Number of moles of gas, n= 1.36

Putting all the values in the above equation,

V=\frac{1.36\times 0.0821\times 273}{1}

V=30.6 L

So the volume will be 30.6 L.

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3 years ago

Deval drew the models of particles in a substance shown below. Which model best represents the particles in solid

adell [148]

Answer:

it would be the second one thank me later

Explanation:

5 0

2 years ago

whoch of the following statments doesnt describe the structure of a atowhich of the following do not describe the structure of a

ra1l [238]

Answer : The incorrect option is, The most of the mass of the atom comes from the electron cloud.

Explanation :

There are three basic particles of an atom which are neutrons, protons and electrons.

The nucleus which is present in the center of an atom that contains the neutrons and the protons. The protons are positively charged and neutrons has no charge.

The outer region of an atom contains the electrons and the electrons are negatively charged.

As per given options, the statement which is the most of the mass of the atom comes from the electron cloud is incorrect statement because the most of the mass comes from the nucleus in which protons and neutrons are present.

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3 years ago