The question here is solved using basic chemistry. CaCl2(aq) is an ionic compound which will have the releasing of 2 Cl⁻ ions ions in water for every molecule of CaCl2 that dissolves.
CaCl2(s) --> Ca+(aq) + 2 Cl⁻(aq)
[Cl⁻] = 0.65 mol CaCl2/1L × 2 mol Cl⁻ / 1 mol CaCl2 = 1.3 M
The answer to this question is [Cl⁻] = 1.3 M
The Avogadro number represents the number of units in one mole of a chemical substance.
So to find the mole number of a chemical element, you divide its atom number of the Avogadro number which Na = 6.02*10^23 approx.
So n=N/Na (n=mole number, N=number of atoms, Na=Avogadro number)
n=1.0*10^15/6.02*10^23
n=1.6 * 10^-9
So 1.0*10^15 atoms of Sodium represent 1.6*10^-9 mol.
Hope this Helps! :)
Answer:
D I think the answer is D for this question
I don't think that "Maxwell's demon" is possible to happen. Take for example a boiling water poured in a glass and cold water poured in the same glass. They each have different temperatures but when they are put together in the same container, the boiling water releases its energy and absorbs some coldness of the cold water and vice versa. In the end, the water temperature will be the average temperature of both types of water. Boiling water and cold water in the same container can never keep their original temperature. It just is not possible. Even if there is a glass partition to separate these waters, heat and coldness will still be transferred between the two through the glass partition.
Compound Formula CuF2
Appearance White crystalline powder
Melting Point 836° C (1,537° F)
Boiling Point 1,676° C (3,049° F)
Density 4.23 g/cm3
Hope I helped
