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Phoenix [80]
3 years ago
9

How many moles does 205g of helium, He contains ?

Chemistry
2 answers:
Ne4ueva [31]3 years ago
7 0
<span>Moles = weight in g / atomic weight So, moles in 40 g of He = 40 / 4 = 10 moles.</span>
Travka [436]3 years ago
7 0
19.512 
i hope this helps

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Which of the following substances would likely dissolve but not dissociate in water
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5 0
2 years ago
21 mL It required 42.35 mL of H2SO4 to neutralize 21.17 mL of 0.5000 M NaOH. Calculate the concentration of H2SO4
bija089 [108]
The balanced equation for the above reaction is 
2NaOH + H₂SO₄ ---> Na₂SO₄ + 2H₂O
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Therefore number of H₂SO₄ moles reacted - 0.010585 /2  mol
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5 0
3 years ago
4 HF(g)+SiO2(s) → SiF4(9)+2 H2O(9) <br> Is the Si oxidized or reduced?
Airida [17]

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8 0
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13. Which statement best describes an element? *
Natasha2012 [34]

Explanation:

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Key Points

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A chemical substance is composed of one type of atom or molecule.

A mixture is composed of different types of atoms or molecules that are not chemically bonded.

A heterogeneous mixture is a mixture of two or more chemical substances where the various components can be visually distinguished.

A homogeneous mixture is a type of mixture in which the composition is uniform and every part of the solution has the same properties.

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Terms

substanceA form of matter that has constant chemical composition and characteristic properties. It is composed of one type of atom or molecule.

elementA chemical substance that is made up of a particular kind of atom and cannot be broken down or transformed by a chemical reaction.

mixtureSomething that consists of diverse, non-bonded elements or molecules.

4 0
3 years ago
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