Yes. Percent yield shows how efficient one's method is. If his isolated caffeine proved to be at only 1.5%, compared to least 50% as in many of the previous experiments, the student should be very concerned as it shows that something caused the yield to sharply drop.
Answer:
0.00840
Explanation:
The computation of the mole fraction is as follow:
As we know that
Molar mass = Number of grams ÷ number of moles
Or
number of moles = Number of grams ÷ molar mass
Given that
Number of moles of CaI2 = 0.400
And, Molar mass of water = 18.0 g/mol
Now Number of moles of water is
= 850.0 g ÷ 18.0 g/mol
= 47.22 mol
And, Total number of moles is
= 0.400 + 47.22
= 47.62
So, Molar fraction of CaI2 is
= 0.400 ÷ 47.62
= 0.00840
Answer:
Sugar is a polar compound , in the solid state of it Hydrogen bond strongly binds the molicules of sugar together. Being a non polar solvent and low polarity difference between Cl and C atom C—Cl bond in CCl4 is unable to form hydrogen bond. That's why sugar can't be soluble in CCl4.
Explanation:
Answer:
False
Explanation:
Temperature is also heat energy, so chemical energy has no affect over it.
Remember that density refers to the "mass per unit volume" of an object.
So, if an object had a mass of 100 grams and a volume of 100 milliliters, the density would be 100 grams / 100 ml.
In the question, water on the surface of the scale would add weight, so the mass of the object that you're weighing would appear to be heavier than it really is. If that happens, you'll incorrectly assume that the density is GREATER than it really is
As an example, suppose that there was 5 ml of water on the surface of the scale. Water has a density of 1 gram per milliliter (1 g/ml) so the water would add 5 grams to the object's weight. If we use the example above, the mass of the object would seem to be 105 grams, rather than 100 grams. So, you would calculate:
density = mass / volume
density = 105 grams / 100 ml
density = 1.05 g/ml
The effect on density would be that it would erroneously appear to be greater
Hope this helps!
Good luck
