Answer:
Magnesium has 2 valence electrons.
Explanation:
The atomic number of magnesium is 12. This means that it has 12 protons and 12 electrons. The first electron shell can hold 2 electrons, the second can hold 8, so the third will have 2 electrons. The outermost shell of the atom has two electrons. Therefore, magnesium has 2 valence electrons.
Answer:
The total energy to break all the bonds in 1 mole of 1-propanol, C₃H₈O, is 4411 kJ/mol
Explanation:
We note that propanol, C₃H₈O is also known as 1-propanol is written as follows;
CH₃CH₂CH₂OH which gives
CH₃-CH₂-CH₂-OH
Hence, the total number of bonds are;
C-H Bonds = 3 + 2 + 2 = 7
C-O Bonds = 1
O-H Bond = 1
C-C Bonds = 2
The bond energies are as follows;
C-H Bonds = 413 kJ/mol
C-O Bonds = 358 kJ/mol
O-H Bond = 468 kJ/mol
C-C Bonds = 347 kJ/mol
Energy required to break the bonds in 1-propanol is therefore;
C-H Bonds = 413 kJ/mol × 7 = 2,891 kJ/mol
C-O Bonds = 358 kJ/mol × 1 = 358 kJ/mol
O-H Bond = 468 kJ/mol × 1 = 468 kJ/mol
C-C Bonds = 347 kJ/mol × 2 = 694 kJ/mol
The total energy to break all the bonds in 1 mole of 1-propanol = 4411 kJ/mol.
We can determine the empirical formula by first converting each of the grams to moles. remember to do this, first, we need the molar mass of the molecules which can be calculated by adding the mass of the atoms from the periodic table.
molar mass of CO2= 44.0 g/mol
molar mass of H2O= 18.02 g/mol
now, lets determine the grams of each atom
Carbon: 23.98 g x (12.011 g / 44.01 g) = 6.54 g C
Hydrogen: 4.91 g x (2.0158 g / 18.02 g) = 0.55 g H
Oxygen: 10.0 - (6.54 + 0.55) = 2.91 g O
Now let's convert each mass to moles.
C: 6.54 g / 12.01 g / mol = 0.54 mol
H: 0.55 g / 1.01 g/mol = 0.54 mol
O: 2.91 g / 16.00 g/mol = 0.18 mol
now that we have the moles of each atom, we need to divide them by the smallest value to find the ration. If you do not get the whole number, you need to multiply until to get a whole number.
C: 0.54 mol / 0.18 mol = 3
H: 0.54 mol / 0.18 mol = 3
O: 0.18 mol / 0.18 mol = 1
empirical formula--> C₃H₃O
The number of particles : 2.75 x 10²¹
<h3>Further explanation </h3>
A mole is a unit of many particles (atoms, molecules, ions) where 1 mole is the number of particles contained in a substance that is the same amount as many atoms in 12 gr C-12
1 mole = 6.02.10²³ particles
N = number of particles
No = Avogadro number (6.02.10²³)
n = number of moles
While the number of moles can also be obtained by dividing the mass (in grams) with the molar mass of element or molecule
0.75 gram sample of Calcium Nitrate; Ca(NO₃)₂
MW of Ca(NO₃)₂ : 164.09 g/mol
The number of particles
