Answer:
Percent yield = 69.4%
Explanation:
Given data:
Percent yield = ?
Actual yield of copper = 4.65 g
Mass of aluminium = 1.87 g
Mass of copper sulfate = excess
Solution:
Chemical equation:
2Al + 3CuSO₄ → Al₂(SO₄)₃ + 3Cu
Number of moles of Aluminium:
Number of moles = mass/ molar mass
Number of moles = 1.87 g/27 g/mol
Number of moles = 0.07 mol
Now we will compare the moles of Al with copper.
Al : Cu
2 : 3
0.07 : 3/2×0.07 =0.105 mol
Mass of Copper:(Theoretical yield)
Mass = Number of moles × molar mass
Mass = 0.105 mol × 63.5 g/mol
Mass = 6.7 g
Percent yield:
Percent yield = Actual yield / theoretical yield × 100
Percent yield = 4.65 g/ 6.7 g × 100
Percent yield = 69.4%
Answer:
They contain of atoms
Explanation:
That's because atomic weights or masses of each atom of each element are proportional to each other, the same number of atoms of each element will give masses that are also proportional to each other. If you start with 20 oxygen atoms, you will need 40 hydrogen atoms to make the water and you will get 20 molecules of water.
By Gay Lussacs law you can find the pressure. First both temperatures of Celsius must change to Kelvin by adding 273. Temperature one will be 308K and temperature 2 will be 258K
With this info, you can now find the pressure with Lussacs law
P1 = P2
— —
T1 T2
Pressure 1 is given which is 32 psi so just plug it all in and find P2
32 = x
—— ——
308 258
308x = 8256 (Cross multiply)
X = 26.8 (divide both sides by 308)
Answer is 26.8 PSI
This makes sense because as temperature increases pressure increases, as well as when temperature decreases, pressure decreases. Since it’s a colder day the pressure will be lower.
Answer:
Ammonia is the richest source of nitrogen on a mass percentage basis because it has 82.35% of nitrogen by mass.
Explanation:
Percentage of element in compound :
(a) Urea, 
Molar mass of urea = 60 g/mol
Atomic mass of nitrogen = 14 g/mol
Number of nitrogen atoms = 2
(b) Ammonium nitrate, 
Molar mass of ammonium nitrate = 80 g/mol
Atomic mass of nitrogen = 14 g/mol
Number of nitrogen atoms = 2
(c) Nitric oxide, NO
Molar mass of nitric oxide = 30 g/mol
Atomic mass of nitrogen = 14 g/mol
Number of nitrogen atoms = 1
(d) Ammonia, 
Molar mass of ammona = 17 g/mol
Atomic mass of nitrogen = 14 g/mol
Number of nitrogen atoms = 1
Ammonia is the richest source of nitrogen on a mass percentage basis because it has 82.35% of nitrogen by mass.
They are called precipitates.
