Answer:
3.481 x 10²⁴ atoms
Explanation:
Data Given:
Number of moles of NH₄NO₃ = 5.78 mol
Number of atoms of NH₄NO₃ = ?
Solution:
Formula used
no. of moles = no. of atoms / Avogadro's number
As we have to find no. of atoms
So, we have to rearrange the above equation
no. of atoms = no. of moles x Avogadro's number . . . . . (1)
Where
Avogadro's number = 6.022 x 10²³ atoms
Put values in above Equation 1
no. of atoms = 5.78 mol x 6.022 x 10²³ atoms/mol
no. of atoms = 3.481 x 10²⁴ mol
So,
no. of atoms in 5.78 mole NH₄NO₃ = 3.481 x 10²⁴ atoms
In order to answer this question, we are going to look at the molar ratio between H2O and H2, we can see that by analyzing the numbers in front of the compounds, and we can see that the molar ratio is 2:2, this means that for every 2 moles of water decomposing, we will end up with 2 moles of H2 being produced, therefore the same amount of moles for H2O will be the same amount of moles of H2, which means that if we have 100 moles of H2O being decomposed, we will also have 100 moles of H2 being produced.
Half life is the time taken by a radioactive isotope to decay by half its original mass.
The original mass is 200 g
Time taken is 60 hours
Final mass is 25 g
Therefore;
Final mass = Original mass × (1/2)^n; where n is the number of half lives.
25 = 200 (1/2)^n
1/8 = (1/2)^n
n = 3
Three half lives = 60 hours
1 half lives = 20 hours
Therefore; the half life of the radioactive nucleus is 20 hours
Meteorologist.............................
