Answer:
They are held together by hydrogen bonds
Explanation:
Hydrogen bonds are special dipole-dipole attractions between polar molecules in which a hydrogen atom is directly joined to a highly electronegative atom(oxygen or nitorgen or fluorine).
Such molecules includes water, alkanoic acids, ammonia and amines.
A hydrogen nucleus has a high concentration of positive charge. The bond is actually an electrostatic attraction between the hydrogen atom of one molecule and the electronegative atom(O or N or F).
Hydrogen bonds are very effective in binding molecules into larger units. Most substances that joins with hydrogen bonds have a higher boiling point and lower volatility.
This is why we have a strong intermolecular bond between water molecules.
Answer:
We could do two 1:50 dilutions and one 1:4 dilutions.
Explanation:
Hi there!
A solution that is 1000 ug/ ml (or 1000 mg / l) is 1000 ppm.
Knowing that 1 ppm = 1000 ppb, 100 ppb is 0.1 ppm.
Then, we have to dilute the stock solution (1000 ppm / 0.1 ppm) 10000 times.
We could do two 1:50 dilutions and one 1:4 dilutions (50 · 50 · 4 = 10000). Since the first dilution is 1:50, you will use the smallest quantity of the stock solution (if we use the 10.00 ml flask):
First step (1:50 dilution):
Take 0.2 ml of the stock solution using the third dispenser (20 - 200 ul), and pour it in the 10.00 ml flask. Fill with water to the mark (concentration : 1000 ppm / 50 = 20 ppm).
Step 2 (1:50 dilution):
Take 0.2 ml of the solution made in step 1 and pour it in another 10.00 ml flask. Fill with water to the mark. Concentration 20 ppm/ 50 = 0.4 ppm)
Step 3 (1:4 dilution):
Take 2.5 ml of the solution made in step 3 (using the first dispenser 1 - 5 ml) and pour it in a 10.00 ml flask. Fill with water to the mark. Concentration 0.4 ppm / 4 = 0.1 ppm = 100 ppb.
Answer:
A
Explanation:
If the Picture is a Desert showing reptiles like lizards and has cacti then it would be Dry and Sandy
Answer:
Potassium chloride
Explanation:
A solution is formed by a solvent and one or more solutes.
The solvent is the species that is in major proportion and usually defines the state of aggregation of the solution, while the solute/s is/are in minor proportion.
Also, water is known as the universal solvent, so in any solution containing water, it is considered as the solvent.
Then, in an aqueous solution of potassium chloride the solute is potassium chloride.
