The Aufbau principle states that, hypothetically, electrons orbiting one or more atoms fill the lowest available energy levels before filling higher levels (e.g., 1s before 2s). In this way, the electrons of an atom, molecule, or ion harmonize into the most stable electron configuration possible.
Answer:

Explanation:
In order to answer this question, we need to be familiar with the law of freezing point depression. The law generally states that mixing our solvent with some particular solute would decrease the freezing point of the solvent.
This may be expressed by the following relationship:

Here:
is the change in the freezing point of the solvent given its initial and final freezing point temperature values;
is the van 't Hoff factor (i = 1 for non-electrolyte solutes and i depends on the number of moles of ions released per mole of ionic salt);
is the freezing point depression constant for the solvent;
is molality of the solute, defined as a ratio between the moles of solute and the mass of solvent (in kilograms).
We're assuming that you meant 1.7-molal solution, then:

Given ethylene glycol, an organic non-electrolyte solute:

The freezing point depression constant:

Initial freezing point of pure water:

Rearrange the equation for the final freezing point and substitute the variables:

Answer:
cis 2,3-dibromo- 2-butene
trans 2,3-dibromo- 2-butene
Explanation:
The cis-trans or geometric isomerism is due to restricted rotation around a carbon-carbon bond. This restriction may be due to the presence of double bonds or cycles.
The carbon-carbon double bond prevents free rotation of atoms in molecules. These two molecules have the same atoms, but they are different molecules. They are geometric isomers to each other.
The given compound can exist in the form of two isomers, cis and trans. The isomer that has the substituents on the same side is called cis, and the one that has them on opposite sides is trans.
Answer:
exothermic
Explanation:
heat/energy is released when it burns.