Answer:
I think that a pure substance is a form of matter that has a constant composition and properties that are constant throughout the sample. Mixtures are physical combinations of two or more elements and/or compounds.
Explanation:
Answer
Naphthalene is a non electrolyte
If the unknown compound is an electrolyte it gives 2 or more ions in solution
( NaCl >> Na+ + Cl- => 2 ions
Ca(NO3)2 >> Ca2+ + 2 NO3- => 3 ions)
the f.p. lowering is directly proportional to the molal concentration of dissolved ions in the solution )
For naphthalene
delta T = 1.86 x m
for a salt that gives 2 ions
delta T = 1.86 x m x 2
hence the lowering in freezion point of unkown is greater then napthalene
Answer:
These substances are called amphiprotic. Water, amino acids, hydrogen carbonate ions, and hydrogen sulfate ions are common examples.
Explanation:
A substance is amphoteric (from Greek amphoteros = "each of two") if it can act as an acid or a base.
For example, aluminum hydroxide is amphoteric because it can act as a base and neutralize strong acids.
Answer:
D. The cork looked like tiny rectangular rooms
Explanation:
The invention that helped scientists discover the cell is the microscope. Tell why Hooke called the structures he saw in the cork cellular("small rooms"). He called them cellular because the box like cells reminded him of the monks monasteries.
