Answer: 45
Explanation:
Recall that mass number = number of protons + number of neutrons. Hence, the mass number of the atom
= 22 + 23
= 45
Furthermore, the atomic number is equal to the number of protons. Hence, since the number of protons is 22. the atom has an atomic number of 22
Thus, An atom that contains 22 protons,
23 neutrons, and 22 electrons would have a mass of approximately 45
Scientists should control most possible variables in experiments to get the most valid and correct data. If many variables are included in experiments it is more difficult to interpret what is causing a different outcome.
Answer : 0.8663 Kg of chalcopyrite must be mined to obtained 300 g of pure Cu.
Solution : Given,
Mass of Cu = 300 g
Molar mass of Cu = 63.546 g/mole
Molar mass of 
= 183.511 g/mole
- First we have to calculate the moles of Cu.
The moles of Cu = 4.7209 moles
From the given chemical formula, we conclude that the each mole of compound contain one mole of Cu.
So, The moles of Cu = Moles of = 4.4209 moles
- Now we have to calculate the mass of .
Mass of = Moles of × Molar mass of = 4.4209 moles × 183.511 g/mole = 866.337 g
Mass of = 866.337 g = 0.8663 Kg (1 Kg = 1000 g)
Therefore, 0.8663 Kg of chalcopyrite must be mined to obtained 300 g of pure Cu.
Answer:
Less
Explanation:
Since [Cu(NH3)4]2+ and [Cu(H2O)6]2+ are Octahedral Complexes the transitions between d-levels explain the majority of the absorbances seen in those chemical compounds. The difference in energy between d-levels is known as ΔOh (ligand-field splitting parameter) and it depends on several factors:
- The nature of the ligand: A spectrochemical series is a list of ligands ordered on ligand strength. With a higher strength the ΔOh will be higher and thus it requires a higher energy light to make the transition.
- The oxidation state of the metal: Higher oxidation states will strength the ΔOh because of the higher electrostatic attraction between the metal and the ligand
A partial spectrochemical series listing of ligands from small Δ to large Δ:
I− < Br− < S2− < Cl− < N3− < F−< NCO− < OH− < C2O42− < H2O < CH3CN < NH3 < NO2− < PPh3 < CN− < CO
Then NH3 makes the ΔOh higher and it requires a higher energy light to make the transition, which means a shorter wavelength.
Answer:
Molality = 7.5 mol/kg
Explanation:
Given data:
Mass of NH₄Cl = 6.30 g
Mass of water = 15.7 g (15.7/1000 =0.016 kg)
Molality = ?
Solution:
Formula of molality:
Molality = Moles of solute / mass of solvent in gram
Now we will first calculate the number of moles of solute( NH₄Cl )
Number of moles = mass/ molar mass
Molar mass of NH₄Cl = 53.491 g/mol
Number of moles = 6.30 g/ 53.491 g/mol
Number of moles = 0.12 mol
Now we will calculate the molality.
Molality = Moles of solute / mass of solvent in gram
Molality = 0.12 mol / 0.016 kg
Molality = 7.5 m
or (m=mol/kg)
Molality = 7.5 mol/kg
