Answer:
-0.93 °C
Explanation:
Hello,
The freezing-point depression is given by:
Whereas 
is the freezing temperature of the solution, 
is the freezing temperature of the pure solvent (0 °C since it is water), 
the Van't Hoff factor (1 since the solute is covalent), 
the solvent's freezing point depression point constant (in this case 
) and 
the molality of the glucose.
As long as the unknown is , solving for it:
Best regards.
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.
Energy is absorbed in the reaction
<span>The electronic configuration of cobalt is :1s2 2s2 2p6 3s2 3p6 3d7 4s2 </span>
First off there are some issues in your questions but I can still help in answering this type of problem. First, there is no Sr-20. The 4 abundant form includes Sr-84, Sr-88, Sr-87, Sr-86, Sr-84.
More importantly, the half life of strontium must be given.
For demonstration sake, let us assume Sr-85 is the isotope. It has a half-life of 64.853 days and I'm assuming the units of 87.3 is in days.
A/Ao = e^-(ln2/t)T
where A- final amount Ao -initial amount t- halflife T-total time elapsed
% = <span>e^-(ln2/64.853)(87.3) = 0.3933 or 39.33%
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