How many hydrogen atoms are there in a 5 sample of pure hydrogen?

In summary, to determine the number of hydrogen atoms in a 5 gram sample of pure hydrogen, we can use Avogadro's number. The number of hydrogen atoms does not depend on the physical state of the sample and cannot be measured directly. It also does not change over time. Hydrogen typically has the highest number of atoms per gram compared to other elements.
  • #1
convict4703
3
0
How many hydrogen atoms are there in a 5 sample of pure hydrogen?
 
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  • #2
What is a "5 sample"?
 
  • #3
sorry, a 5g sample.
 
  • #4
Well, can you think of any formulae that can help you find this out? Does Avogadro's number ring a bell?
 
  • #5
This looks like homework.
Number of atoms = Number of moles * Avogadro's Number
Use that with the molecular weight of Hydrogen for your answer.
 

1. How do you determine the number of hydrogen atoms in a 5 gram sample of pure hydrogen?

The number of hydrogen atoms in a sample can be determined using the Avogadro's number, which is 6.022 x 10^23. This number represents the number of particles (atoms or molecules) in one mole of a substance. Therefore, to find the number of hydrogen atoms in a 5 gram sample, we need to convert the mass of the sample to moles by dividing it by the molar mass of hydrogen (1 gram/mol). This gives us 5 moles. Then, we multiply the number of moles by Avogadro's number to get the total number of hydrogen atoms, which is 3.011 x 10^24.

2. Does the number of hydrogen atoms in a sample depend on its physical state?

No, the number of hydrogen atoms in a sample remains the same regardless of its physical state. This is because the number of atoms in a given sample is determined by its mass and the atomic composition of the substance, which does not change with state changes (solid, liquid, gas).

3. Can the number of hydrogen atoms in a sample be measured directly?

No, the number of hydrogen atoms in a sample cannot be measured directly. Instead, it is calculated using the method mentioned in the first question. This is because individual atoms are too small to be counted and require specialized equipment such as scanning tunneling microscopes to visualize.

4. Does the number of hydrogen atoms in a sample change over time?

No, the number of hydrogen atoms in a sample does not change over time. This is because atoms are not created or destroyed, they only rearrange in chemical reactions. Therefore, the number of atoms in a closed system remains constant.

5. How does the number of hydrogen atoms in a sample compare to other elements?

The number of hydrogen atoms in a sample can vary depending on the mass and atomic composition of the substance. However, in general, hydrogen is the lightest element and therefore has the highest number of atoms per gram compared to other elements. For example, a 5 gram sample of pure oxygen would have 2.5 x 10^23 atoms, while a 5 gram sample of pure carbon would have 1.25 x 10^23 atoms.

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