Which of the following is a property of a pure substance?

a.) it can be chemically separated if it is a compound.

b.) it’s components can be separated with ease.

c.) it is made up of two or more types of compounds .

d.) the original components retain their individual properties

D.) The original components retain their individual properties

Explanation:

A pure substance is a substance of constant chemical composition throughout its mass some of the examples of the pure substances are iron, water, oxygen gas, nitrogen gas etc.

A pure substance can in the form of solid, liquid or gas which have constant property. Two or more pure substances combines together to from a mixture after which is not said to be pure substance

For example the one or more atom of the same element is said to be pure but the molecule of two different elements is not said to be a pure substance as they have different property of both of the elements like H2 and H2O where H2 is a pure substance and H2O is not a pure substance.

The pure shows their individual property if they are not combined with other elements or substance as it will not posses individual property.

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