Answer:
Mass = 785.9 g
Explanation:
Given data:
Atoms of gold = 2.4 × 10²⁴ atoms
Mass of gold = ?
Solution:
First of all we will convert the number of atoms into moles.
2.4 × 10²⁴ atoms × 1 mol/ 6.02 × 10²³ atoms
number of moles = 3.99 mol
Now we will determine the mass of gold.
Mass = number of moles × molar mass
Mass = 3.99 mol × 196.97 g/mol
Mass = 785.9 g
Answer:
Molality is 0.25 m
Explanation:
Molality → Moles of solute / kg of solvent
We need the moles of solute → 0.124 moles
22.4 g . 1 mol / 180 g = 0.124 moles
We need the mass of solvent in kg. We determine the mass of solvent with density.
Density = Mass / Volume
Mass = Density . volume → 1 g/mL . 500 mL = 500 g
If we convert the mass in g to kg → 500 g . 1kg / 1000 g = 0.5 kg
In conclussion, molality → 0.124 mol / 0.5 kg = 0.25 m
The percentage yield of the reaction : 93.3%
Mass of FeCO₃ 2310.44 g
<h3>Further explanation
</h3>
The reaction equation is the chemical formula of reagents and product substances
A reaction coefficient is a number in the chemical formula of a substance involved in the reaction equation. The reaction coefficient is useful for equalizing reagents and products
Reaction
4 FeCO₃ + O₂ ⇒ 2 Fe₂O₃ + 4CO₂
MW FeCO₃ : 115,854 g/mol
MW Fe₂O₃ : 159,69 g/mol




mol of 1 kg Fe₂O₃ = 1000 g

mol of FeCO₃

mass of FeCO₃

a purity of 62.8%

Answer:
- Please, find the drawing in the picture attached.
Explanation:
A simple model or drawing of the structure of an atom may be performed showing the electrons on the different energy levels (shells), plus the nucleons (protons and neutrons).
Then, you need the information on:
- number of protons (atomic number)
- electron configuration
- number of neutrons
The first step is to find the atomic number of the atom. You find that information in the periodic table, where the elements are show with their chemical symbol.
The chemical symbol of sodium is Na. It is located in the group (colum) 1 and period (raw) 3. There you find that the atomic number is 11. Hence your drawing must show 11 protons.
Since the atom is neutral, the number of electrons is also 11. So, you must place the electrons in the following energy levels or shells:
Main energy level shell number of electrons
n = 1 K 2 (this is the maximum in this level)
n= 2 L 8 (this is the maximun in this level)
n= 3 M 1 (the maximum in this level is 18)
Now that you have the number of protons and the location of the electrons, you must determine the number of neutrons.
In the periodict table you will also find the atomic mass of the elements. The atomic mass of sodium is 22.990 amu. That means that most sodium atoms have mass number (number of protons plus neutrons) 23. Some isotopes will have less neutrons, but you can draw your model using the most typical isotope with 23 nucleons. This means, that the number of neutrons is 23 nucleons - 11 protons = 12 neutrons.