<span>the molar mass of a compound is the sum of the products of the atomic masses by the number of atoms of the element.
molar mass of Na</span>₂SO₄<span> is - 142 g/mol.
1 mol of </span>Na₂SO₄<span> has a mass of 142 g.
In 1 mol of </span>Na₂SO₄<span> the mass of Na is 23 g/mol x 2 = 46 g.
Mass of Na in 1 mol of </span>Na₂SO₄ is - 46 g
mass of Na in 0.820 mol of Na₂SO₄ - 46 g /1 mol x 0.820 mol = 37.72 g.
mass of Na is 37.72 g
Answer:
Not D.
Explanation:
I saw the answer somewhere else on brainly and i took the test and it was wrong
Firstly, Ionic solids can't conduct electricity, this is because of the close packed structure partly caused by the strong attraction between the delocalised electrons and the positively charged ions in the lattice structure (the close packed structure is also partially due to the fact it is in a solid state, it's not just solely to the ionic bonds). As the structure is so close packed, the ions are not free to move so electricity cannot be conducted.
Secondly, high melting and boiling points (counts as a physical property as it can be observed) as there is high attraction between the oppositely charged entities in the ionic lattice, added to by the sheer number of ionic bonds and resulting electrostatic attraction in a lattice (aka strong and plentiful ionic bonds) mean lots of energy is needed to overcome these bonds in order to change state.
Thirdly, they are usually hard and brittle as the lattice is a huge structure that is held rigidly in place by the strong electrostatic attraction arising from the ionic bonds.
To solve the question we will assume that the gas behaves like an ideal gas, that is to say, that there is no interaction between the molecules. Assuming ideal gas we can apply the following equation:
Where,
P is the pressure of the gas
V is the volume of the gas
n is the number of moles
R is a constant
T is the temperature
Now, we have two states, an initial state, and a final state. The conditions for each state will be.
Initial state (1)
P1=975Torr=1.28atm
V1=3.8L
T1=-18°C=255.15K
Final state(2), STP conditions
P2=1atm
T2=273.15K
V2=?
We will assume that the number of moles remains constant, so the nR term of the first equation will be constant. For each state, we will have:
Since nR is the same for both states, we can equate the equations and solve for V2:
We replace the known values:
At STP conditions the gas would occupy 5.2L. First option
Balanced chemical reaction: 2HI(aq) + Ba(OH)₂(aq) → BaI₂(aq) + 2H₂O(l).
Ionic reaction: 2H⁺ + I⁻(aq) + Ba²⁺ + 2OH⁻(aq) → Ba²⁺ + 2I⁻(aq) + 2H₂O(l).
Net ionic reaction: 2H⁺ + 2OH⁻(aq) → 2H₂O(l).
Barium iodide is salt that dissolves in water, barium hydroxide is strong base that dissolves in water.
This is example of double replacement reactions(double displacement or metathesis reactions), two ionic compounds are exchanged, making two new compounds
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