Answer:
The answer to your question is 24.325
Explanation:
Data
Magnesium-24 Abundance = 78.70%
Magnesium-25 Abundance = 10.13%
Magnesium-26 Abundance = 11.17%
Process
1.- Convert the abundance to decimals
Magnesium-24 Abundance = 78.70/100 = 0.787
Magnesium-25 Abundance = 10.13/100 = 0.1013
Magnesium-26 Abundance = 11.17/100 = 0.1117
2.- Write an equation
Average atomic mass = (Atomic mass-1 x Abundance 1) + (Atomic mass 2 x
Abundance-2) + (Atomic mass 3 x Abundance 3)
3.- Substitution
Average atomic mass = (24 x 0.787) + (25 x 0.1013) + (26 x 0.1117)
4.- Simplification
Average atomic mass = 18.888 + 2.533 + 2.904
5.- Result
Average atomic mass = 24.325
Answer:
Explanation:
If we want to convert from grams to moles, the molar mass is used. This is the mass of 1 mole. They are found on the Periodic Table as the atomic masses, but the units are grams per mole (g/mol) instead of atomic mass units (amu).
Look up the molar mass of carbon.
Set up a ratio using the molar mass.
Since we are converting 3.06 grams to moles, we multiply by that value.
Flip the ratio. This way, the ratio is still equivalent, but the units of grams of carbon cancel.
The original measurement of grams (3.06) has 3 significant figures, so our answer must have the same. For the number we calculated, that is the thousandth place.
The 7 in the ten-thousandth place tells us to round the 4 up to a 5.
3.06 grams of carbon is approximately <u>0.255 moles of carbon.</u>
Answer:
Nitrogen is limiting reactant while hydrogen is in excess.
Explanation:
Given data:
Mass of N₂ = 25 g
Mass of H₂ = 25 g
Mass of ammonia formed = ?
Solution:
Chemical equation:
N₂ + 3H₂ → 2NH₃
Number of moles of Nitrogen:
Number of moles = mass/ molar mass
Number of moles = 25 g/ 28 g/mol
Number of moles = 0.89 mol
Number of moles of hydrogen:
Number of moles = mass/ molar mass
Number of moles = 25 g/ 2 g/mol
Number of moles = 12.5 mol
Now we will compare the moles of both reactant with ammonia.
H₂ ; NH₃
3 : 2
12.5 : 2/3×12.5 = 8.3
N₂ ; NH₃
1 : 2
0.89 : 2×0.89 = 1.78
The number of moles of ammonia produced by nitrogen are less thus nitrogen is limiting reactant while hydrogen is in excess.
