Select the correct answer.
which statement describes both homogeneous mixtures and heterogeneous mixtures?

a.
their components can be distinguished visually.
b.
their components are combined in a fixed ratio.
c.
their components can be separated by physical processes.
d.
they always contain a liquid component.
e.
they are considered to be pure substances.

C. Their components can be separated by physical processes.  

Explanation:

The components of any mixture can be separated by physical means.

A. is wrong. This is a property of heterogeneous mixtures.

B. is wrong. This is a property of compounds.

D. is wrong. For example, air is a mixture of gases and brass is a mixture of solids.

E. is wrong. Only elements and compounds are pure substances.

given:

mass of na = 115 g

excess cl2

to determine:

mass of nacl produced

explanation:

given reaction is-

2na(s) + cl2(g) → 2nacl(s)

since cl2 is in excess, na will be the limiting reagent

as per the reaction stoichiometry na: nacl = 1: 1

i.e. moles of na reacted = moles of nacl formed

now, # moles of na = mass of na/atomic mass

                                  = 115 g/23 g.mol-1 = 5 moles

therefore, moles of nacl = 5

molar mass of nacl = 58 g/mol

mass of nacl = 5 moles * 58 g.mol-1 = 290 g

ans: amount of nacl produced = 290 g

the electrical  conductivity  of asolution  of an electrolyte is measured by determining the resistance of thesolution  between two flat or cylindrical electrodes separated by a fixed distance.