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3 years ago

Is bleaching hair a physical or chemical change

Chemistry

1 answer:

Greeley [361]3 years ago

8 0

Bleaching hair i a physical change i think; it washes the pigments out.

i hope this helps (;

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Explain how many protons, neutrons, and electrons can be found in an atom of carbon-12.

andriy [413]

A typical atom has six protons and six neurons, and it has an atomic weight of 12 Amu. A carbon also has six electrons, but they are so small that they don’t contribute to carbons weight. An element is defined by the number of protons in its nucleus

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2 years ago

A<br> Write a description of how you know a chemical reaction<br> is occurring

PilotLPTM [1.2K]

Answer: Some signs of a chemical change are a change in color and the formation of bubbles. The five conditions of chemical change: color change, formation of a precipitate, formation of a gas, odor change, temperature change

Explanation:

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2 years ago

(Thermodynamics)

Setler79 [48]

Answer:

456 kJ

Step-by-step explanation:

CH₄ + 2Cl₂ ⟶ CCl₄ + 2H₂ ; ΔH = 45.6 kJ

Treat the heat as if it were a product in the equation. Then use the molar ratio (45.6 kJ/2 mol Cl₂) in the usual way.

Amount of energy = 20 mol Cl₂ × (45.6 kJ/2 mol Cl₂) = 456 kJ

You must add 456 kJ to react 20 mol of chlorine with excess methane.

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3 years ago

Please help me<br>will give the brainliest!

Scorpion4ik [409]

Explanation:

a) The presence of sulfate ions in a solution can be confirmed by the reaction of barium chloride in an acidic medium.

The balanced chemical equation of the reaction is shown below:

$BaCl_2(aq)+CuSO_4(aq)->CuCl_2(aq)+BaSO_4(s)$

Hence, the white precipitate is barium sulfate and its formation with the ionic equation is shown below:

$Ba^2^+(aq)+SO_4^2^-(aq)->BaSO_4(aq)$

b) The presence of copper (II) ions can be confirmed by the following test:

Add potassium iodide solution to copper (II) solution.

Then a white ppt of cuprous iodide along with the liberation of iodine is observed and the entire solution attains brown color.

The chemical equation of the reaction is shown below:

$2CuSO_4(aq)+4KI(aq)->Cu_2I_2(s)+I_2(s)+2K_2SO_4(aq)\\$

c)(i)Due to this reaction, the blue color of the solution becomes white.

Reddish-brown copper is deposited at the bottom of the container.

(ii)In this reaction, zinc is oxidized.

d) (i) Copper is produced at the cathode.

(ii) $Cu^2^+(aq)+2e^-->Cu(s)$

(iii) The reaction that takes place at the cathode is reduction.

Reduction is gaining of electrons.

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3 years ago

Explain the process of polymerisation

svlad2 [7]

In polymer chemistry, polymerization is a process of reacting monomer molecules together in a chemical reaction to form polymer chains or three-dimensional networks. There are many forms of polymerization and different systems exist to categorize them.

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3 years ago