A reaction produces 0.819 moles of H2O

A reaction produces 0.819 moles of H2O. How many molecules are produced?

The correct answer and explanation is :

Final Answer:

The number of molecules produced = 4.93 × 10²³ molecules.


Full Explanation:

In this problem, you are given the amount of water produced in moles and asked to find out how many individual molecules of water (H₂O) that represents.

To solve this, you need to know about Avogadro’s number, which is a fundamental constant in chemistry:

  • Avogadro’s number = ( 6.022 \times 10^{23} ) particles (atoms, molecules, ions, etc.) per mole.

This number tells us that one mole of any substance contains exactly ( 6.022 \times 10^{23} ) of its representative particles.


Step 1: Set up the conversion

Since 1 mole = ( 6.022 \times 10^{23} ) molecules, if you have 0.819 moles of H₂O, you can find the number of molecules by multiplying:

[
\text{Number of molecules} = 0.819 \times (6.022 \times 10^{23})
]


Step 2: Perform the calculation

First multiply the numbers:

[
0.819 \times 6.022 = 4.931
]

Then attach the ( 10^{23} ):

[
4.931 \times 10^{23}
]

Thus:

[
\text{Number of molecules} = 4.93 \times 10^{23} \text{ molecules}
]


Step 3: Double-check units

  • Moles cancel out.
  • The answer is correctly left in molecules, which is the quantity the question asked for.

Summary:

  • Given: 0.819 moles of H₂O
  • Use: Avogadro’s number ( (6.022 \times 10^{23}) )
  • Multiply: ( 0.819 \times 6.022 \times 10^{23} )
  • Result: ( 4.93 \times 10^{23} ) molecules of H₂O

Understanding this process is very important because converting between moles and particles is a skill used in almost all areas of chemistry, especially when studying chemical reactions, stoichiometry, and molecular behavior!

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