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AysviL [449]
3 years ago
7

7.89 x 1021 particles is equal to how many moles?

Chemistry
1 answer:
MrMuchimi3 years ago
3 0

Answer:

<h2>0.013 moles</h2>

Explanation:

To find the number of moles in a substance given it's number of entities we use the formula

n =  \frac{N}{L} \\

where n is the number of moles

N is the number of entities

L is the Avogadro's constant which is

6.02 × 10²³ entities

From the question we have

n =  \frac{7.81 \times  {10}^{21} }{6.02 \times  {10}^{23} }  \\  = 0.012973...

We have the final answer as

<h3>0.013 moles</h3>

Hope this helps you

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Carbon dioxide and water react to form methanol and oxygen, like this:
fredd [130]

Answer:

24x10³

Explanation:

2CO₂(g) + 4H₂O(g) → 2CH₃OH(l) + 3O₂ (g)

The equilibrium constant for this reaction is:

Kc = \frac{[O_2]^3}{[CO_2]^2[H_2O]^4}

The expression of [CH₃OH] is left out as it is a pure liquid.

Now we <u>convert the given masses of the relevant species into moles</u>, using their <em>respective molar masses</em>:

  • CO₂ ⇒ 3.28 g ÷ 44 g/mol = 0.0745 mol CO₂
  • H₂O ⇒ 3.86 g ÷ 18 g/mol = 0.214 mol H₂O
  • O₂ ⇒ 2.80 g ÷ 32 g/mol = 0.0875 mol O₂

Then we calculate the concentrations:

  • [CO₂] = 0.0745 mol / 7.5 L = 0.0099 M
  • [H₂O] = 0.214 mol / 7.5 L = 0.0285 M
  • [O₂] = 0.0875 mol / 7.5 L = 0.0117 M

Finally we <u>calculate Kc</u>:

  • Kc = \frac{0.0117^3}{0.0099^2*0.0285^4} = 24x10³

3 0
3 years ago
In a salt water solution, what is the water?
antoniya [11.8K]
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3 years ago
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Why does a group of warmer atoms take up more volume than a group of cooler atoms ?
const2013 [10]
Warmer atoms expand. There is also more movement. This is also explained when putting it into terms with solid vs. gas. in a solid, the atoms vibrate, but they can't move very far because there is not a lot of space between them. In a gas, on the other hand, the atoms are spread apart, and they move very fast. Putting it into context with water, the steam (gas) version is hot, and the ice cube (solid) version is cold.
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4 years ago
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Which element(s) is/are not balanced in this equation? <br> Pb(NO3)2 +2 Kcl -&gt; pbCl2 + KNO3
UkoKoshka [18]

Answer:

The correct answer is KNO3

Explanation:

Pb(NO3)2 +2 KCl -> PbCl2 + KNO3

If we look at the left side of the equation we could see that there are 1 lead atom, 2 nitrate atoms ,2 potassium atoms and 2 chlorine atoms

Now when we look at the right side of the equation, we found that there are –  

1 lead atom and  2 chlorine atoms (PbCl2)  , thus lead and chlorine are balanced as they have the same number of atom in LHS and RHS

There is only 1 potassium and 1 nitrate atom on RHS , thus KNO3 is not balanced.  

The balanced equation would be –  

Pb(NO3)2 +2 KCl -> PbCl2 +2 KNO3

4 0
3 years ago
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IF CONSTRUCTIVE INTERFERENCE PRODUCES A WAVE WITH
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Answer:

This means that the wave is bigger because amplitude is the hight of the crest of the wave!

Explanation:

SO IT MEANS THE WAVE IS BIGGER AND TALLER :D

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