The answer is: both choices a and b.
The base SI unit for molar mass is kg/mol, but chemist more use g/mol (gram per mole).
For example, the molar mass of fluorine is 38.00 g/mol.
M(F₂) = 2 · Ar(F) · g/mol.
M(F₂) = 2 · 19.00 · g/mol.
M(F₂) = 38.00 g/mol.
Molar mass M represent the mass of a substance (in this example molecule of florine) divided by the amount of substance.
Ar is the atomic weight of a chemical element (in this example fluorine).
Answer:
Positive: a and b
Negative: c
Explanation:
The entropy (S) is the measure of the randomness of the system, and it intends to increase. The randomness can be determined by the energy of the molecules, their velocity and how distance they are between the other molecules.
When the entropy increases, ΔS is positive, when the entropy decreases, ΔS is negative. So, when gasoline mix with air in a car engine, the process intends to continue, the randomness increases and ΔS is positive. When hot air expands, the distance between the molecules increases, so ΔS is positive.
But, when humidity condenses, the molecules stay closer, so there's a decrease in the randomness, then ΔS is negative.
Answer:
+6
Explanation:
We are given;
We are required to determine the oxidation number of S in the compound.
We need to know that;
- The total oxidation number of this compound is Zero
- Oxidation number of Ba metal is +2
- Oxidation number of Oxygen atom is -2
- There is 1 atom of Ba, 1 atom of S and 4 atoms of O in the compound.
Therefore; assuming oxidation number of S is x
Then, (1× 2) + (1 × x) + ( 4 ×(-2)) = 0
2 + x - 8 = 0
x = 6 or +6
Thus oxidation number of Sulfur in BaSO₄ is +6.
<span>The pointer will be above the zero mark</span>
