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2 years ago

What type of changes indicate a chemical change?

Chemistry

2 answers:

Talja [164]2 years ago

4 0

Change of color, change in temperature, change in odor.

Komok [63]2 years ago

3 0

A few examples of changes in chemical change are, a change in the color of the chemical, change in the energy or temperature, and lastly change of odor.

Hope I could help! :)

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The average person in the United States is exposed to the following amount of radiations annually. Rank the following source of

Papessa [141]

<span>#1 is air radon, #2 is x-ray, #3 is ground, #4 is cosmic radiation, #5 is TV tube, #6 is weapons test fallout . That's all I got hope I helped!</span>

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3 years ago

Read 2 more answers

I need help please!Perform the following conversion. Make sure your answer has the correct number of significant digits.

Nuetrik [128]

Answer:

3220000

Explanation:

1kg=10^6 Gg

3.22×10^6

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3 years ago

Which one of the following statements is FALSE? a In a neutralization reaction, an acid reacts with base to produce a salt and H

pishuonlain [190]

Answer: Option (c) is the correct answer.

Explanation:

HF is a weak acid and not a strong acid. This is because fluorine is a highly electronegative atom and when it combines with a hydrogen atom then it will attract the valence electron of hydrogen atom more towards itself.

As a result, it will not dissociates easily to give hydrogen ion. Hence, it acts as a weak acid.

A neutralization reaction is defined as a reaction in which an acid reacts with a base to give salt and water. For example, $HCl + NaOH \rightarrow NaCl + H_{2}O$

It is true that, spectator ions "appear in the total ionic equation for a reaction, but not in the net ionic equation".

Titration is defined as a process in which concentration of an unknown solution is determined using a solution of known concentration.

Thus, we can conclude that the statement HF, HCl, and HNO3 are all examples of strong acids, is false.

7 0

3 years ago

30. The density of an unknown gas at 27°C and 2 atm pressure is equal with density of N2 gas at

Zanzabum

Answer:

Molar mass of the unknown gas is 64.6 g/mol

Explanation:

Let's think this excersise with the Ideal Gases Law.

We start from the N₂. At STP conditions we know that 1 mol of anything occupies 22.4L.

We apply: P . V = n . R . T

5 atm . V = 1 mol . 0.082 . 325K

V = (1 mol . 0.082 . 325K) / 5 atm = 5.33 L

It is reasonable to say that, if we have more pressure, we may have less volume.

As this is the volume for 1 mol of N₂, our mass is 28 g. Then, the density of the nitrogen and the unknown gas is 28 g/5.33L = 5.25 g/L

Our unknown gas has, this density at 27°C and 2 atm.

If we star from this, again: 1 mol of any gas occupy 22.4L at STP, we can calculate the volume for 1 mol at those conditions:

P₁ . V₁ / T₁ = P₂ . V₂ / T₂

1 atm . 22,4L / 273K = 2 atm . V₂ / 300K

Remember that the value for T° is Absolute (T°C + 273)

[ (1 atm . 22.4L / 273K) . 300K] / 2 atm = V₂ → 12.3L

This is the volume for 1 mol of the unknown gas at 2 atm and 27°C

We use density to determine the mass: 12.3 L . 5.25 g/L = 64.6 g

That's the molar mass: 64.6 g/mol

6 0

2 years ago

How we can preserve the wetlands areas of nepal?<br>

Luden [163]

Answer:

Reduce, reuse, and recycle your waste and trash. Protecting the environment helps protect the wetlands, especially since trash can make its way into the water. The best and easiest way to protect the environment is by limiting your household waste.

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2 years ago