Answer:
cream - contains a higher proportion of oil than water
ointment - dr4g mixed in approximately equal proportions of oil and water
i don't know about the other two sorry
A is obviously out because it leads to a volume of 125.0 milliliters of the new solution and gives you a lower concentration than you were aiming for.
D is out because you are adding 75 milliliters of the stock solution, so your concentration would be too high. You only need 25.0 milometers of stock solution per 100 milliliters of the new solution.
C is also out because it leads to 50.0 milliliters stock solution per 100 milliliters of the new solution and hence the wrong concentration.
B is by default the correct answer. It also details the correct technique. First you add the stock solution (This you know from your calculations to be 25 milliliters.) then you add the water up to the volume you needed. (Because the calculations only tell you the total volume of water not what you need to add) You also add the water last so you can rinse the neck of the flask to make sure you also get all the stock solution residue into the stock solution.
I would add the final step of stirring, but B is the only answer that can be correct.
1,000 mL is the same as 10 dL.
Answer:
chloroplasts
Explanation:
In plants, photosynthesis takes place in chloroplasts, which contain the chlorophyll. Chloroplasts are surrounded by a double membrane and contain a third inner membrane, called the thylakoid membrane, that forms long folds within the organelle.
The molarity of H2SO4 is the number of moles in 1 L of solution.
The molarity is 2.0 mol/L
This means that there should be 2 moles in a 1 L solution to make up this molarity.
In this case we need to make up a 5 L solutions with that molarity. Then the amount of moles required are - 2 mol/L x 5 L = 10 mol
