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Maksim231197 [3]
3 years ago
15

I need help with all of them.. please help..

Chemistry
1 answer:
Crazy boy [7]3 years ago
7 0
The answer is not the alphabet
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Why is potassium nitrate classified as an electrolyte?.
ch4aika [34]

Answer: It is a molecular compound. (2) It contains a metal. (3) It can conduct electricity as a solid.

5 0
2 years ago
A 30.7 g sample of Strontium nitrate, Sr(NO3)2•nH2O, is heated to a constant mass of 22.9 g. Calculate the hydration number.
Elodia [21]

Answer:

  • <em>Hydration number:</em> 4

Explanation:

<u>1) Mass of water in the hydrated compound</u>

Mass of water = Mass of the hydrated sample - mass of the dehydrated compound

Mass of water = 30.7 g - 22.9 g = 7.8 g

<u>2) Number of moles of water</u>

  • Number of moles = mass in grams / molar mass

  • molar mass of H₂O = 2×1.008 g/mol + 15.999 g*mol = 18.015 g/mol

  • Number of moles of H₂O = 7.9 g / 18.015 g/mol = 0.439 mol

<u>3) Number of moles of Strontium nitrate dehydrated, Sr (NO₃)₂</u>

  • The mass of strontium nitrate dehydrated is the constant mass obtained after heating = 22.9 g

  • Molar mass of Sr (NO₃)₂ :  211.63 g/mol (you can obtain it from a internet or calculate using the atomic masses of each element from a periodic table).

  • Number of moles of Sr (NO₃)₂ = 22.9 g / 211.63 g/mol =  0.108 mol

<u>4) Ratio</u>

  • 0.439 mol H₂O / 0.108 mol Sr(NO₃)₂ ≈  4 mol H₂O : 1 mol Sr (NO₃)₂

Which means that the hydration number is 4.

4 0
4 years ago
Read 2 more answers
Explain why the available amount of water per person differs between countries
Fudgin [204]

Answer:

because in the different countries it is distributed unevenly.

Explanation:

hope this helps

4 0
2 years ago
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Sound waves are transverse mechanical waves. <br><br> True<br> False
allochka39001 [22]

False

Explanation:

Sound waves are longitudinal mechanical waves.

Mechanical waves are waves that requires a medium to propagate them.

  • A transverse wave is a wave that is propagated perpendicularly to its source.
  • An example is electromagnetic radiation.
  • A longitudinal wave is a wave that is directed parallel to their source.
  • Sound wave is a longitudinal wave.
  • It has series of rarefaction and compression along its travel path.
  • Rarefaction are areas of sparse particles.
  • Compression are areas with dense particles.

learn more:

Sound wave brainly.com/question/3619541

#learnwithBrainly

7 0
3 years ago
Light brings many chemical changes. Can you think of any chemical change brought about by light? ​
strojnjashka [21]

Answer:

MRCORRECT has answered the question

Explanation:

Film photography is another example ofchemical reaction by light. In this example, the chemical compounds coated on the film go through a chemical reaction. ... These plates (usually made of aluminum) are coated with a photosensitive compound consisting of a polymer and a photosensitivechemical system.

4 0
3 years ago
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