Asingle displacement reaction is options:when two couples are dancing on the floor and they each swap partners. now both men are dancing with a new woman. when a couple is dancing on the floor and a single man comes up and asks to dance with the woman. then the woman starts dancing with a new partner and the original man is all alone.

Hi

The answer is option 2: when a couple is dancing on the floor and a single man comes up and asks to dance with the woman. Then the woman starts dancing with a new partner and the original man is all alone.

Explanation:

Single-replacement reaction or single displacement reactions are a type of chemical reactions in which a whole compound reacts with an element in such a way that the element takes place of one of the compound's own elements and sets it free.

For example:

                                      KBr + I -> K + IBr

Potassium Bromide + Iodine -> Iodine(i) Bromide +Potassium  

It is a very common reaction in which iodine reacts with potassium bromide and replaces the place of bromine of potassium bromide. Therefore it is called as single displacement reaction.

Hope it help!

- "the choice that is not an indicator of a chemical change is "state of matter changes". more common than not, chemical reactions produce energy in the form of light or heat. along with energy, they also produce a new substance called the product that could be in any state of matter (solid, gas, or liquid)."

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