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3 years ago

Which of the following is an example of a chemical change?

Chemistry

2 answers:

Lynna [10]3 years ago

6 0

The answer is burning paper

svetoff [14.1K]3 years ago

4 0

Burning paper...chemical changes are permanent and can't return to original form.<span />

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What property of water allows the water to cover the astronauts hand?

Arisa [49]

Answer:

The tendency for water molecules to stick together causes it to causes spheres in space. ... Magnetic-like molecules on water's surface cause the surface to behave like an elastic skin. Each molecule is pulled with equal tension by its neighbors.J

Explanation:

7 0

3 years ago

What substances were found in the innermost regions (within about the inner 0.3 au) of the solar system before planets began to

coldgirl [10]

The answer would be Rocks, metals, hydrogen compounds, hydrogen and helium, all in gaseous form.

5 0

3 years ago

State and explain the relative change in the pH and in the buffer-component concentration ratio, [NaA]/[HA], for each of the fol

BabaBlast [244]

A- and H3O+ interact, causing A-'s concentration to drop and [HA] to rise. As a result, the [NaA]/[HA] ratio declines. Because of the base content, the buffer's pH will be more acidic. The concentration of the acid, HA, has increased while A- has decreased.

What is Acid?

Any material that when dissolved in water has an acidic taste, can alter the colour of some indicators (such as reddening blue litmus paper), can react with some metals (such as iron) to release hydrogen, can combine with bases to produce salts, and can accelerate some chemical reactions (acid catalysis). Acids are examples of organic chemicals that belong to the carboxylic acid, sulfonic acid, and phenol groups as well as the inorganic substances known as the mineral acids, such as sulfuric, nitric, hydrochloric, and phosphoric acids. These chemicals contain one or more hydrogen atoms, which are discharged as positively charged hydrogen ions when they are in solution.

To learn more about Acid, visit:

brainly.com/question/14072179

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2 years ago

The 1995 Nobel Prize in chemistry was shared by Paul Crutzen, F. Sherwood Rowland, and Mario Molina for their work concerning th

Nikolay [14]

Answer:

$\Delta H_{rxn3}=-162.5 kJ/mol$

Explanation:

The reaction we need to calculate:

$O_3 (g) + Cl (g) \longrightarrow ClO (g) + O_2 (g)$

1) $O_3 (g) + ClO (g) \longrightarrow Cl (g) +2 O_2 (g)$

$\Delta H_{rxn}=-122.8 kJ/mol$

We need the ClO in the products side, so we use the inverse of this reaction:

$Cl (g) +2 O_2 (g) \longrightarrow O_3 (g) + ClO (g)$

$\Delta H_{rxn1}=122.8 kJ/mol$

2) $2 O_3 (g) \longrightarrow 3 O_2 (g)$

$\Delta H_{rxn2}=-285.3 kJ/mol$

Now we need to combine this two:

$Cl (g) +2 O_2 (g) + 2 O_3 (g)\longrightarrow O_3 (g) + ClO (g) + 3 O_2 (g)$

$Cl (g) + O_3 (g)\longrightarrow ClO (g) + O_2 (g)$

The enthalpy of reaction:

$\Delta H_{rxn3}=\Delta H_{rxn1}+ \Delta H_{rxn2}=122.8 kJ/mol-285.3 kJ/mol$

$\Delta H_{rxn3}=-162.5 kJ/mol$

4 0

3 years ago

A molar solution is a solution that contains one mole of solute in

BartSMP [9]

Answer:

1 liter of the solution

Explanation:

Molarity or concentration of a solution refers to the number of moles of solute contained in a volume of 1 liter or 1 dm³ solution.
Therefore, the concentration of a solution is calculated by dividing the number of moles of a solute by the volume of the solution.
Concentration is given in mol/L or mol/dm³.
Hence, a molar solution is a solution that contains 1 mole of a solute in 1 liter of the solution. This is equivalent to 1M or 1 mol/L.

7 0

3 years ago