On the way to school, Ellie sat on a bench waiting for her friend. She noticed snow all around her. Later that day, Ellie and her friend walked home and passed the same bench. Ellie's friend said, “There is a puddle in front of the bench. It must have rained while we were in school, creating this puddle.” Ellie disagreed. She had a different claim about how the puddle formed based on the evidence from her observations. Ellie's evidence was as follows:

The park was covered in snow that morning but not in the afternoon.
Ellie didn’t need her jacket on the way home because it was so warm.
It was sunny all day.
Do you think the puddle was formed from rain? Why or why not?

what's the

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

a: 45.9 meters

b: 4.29 seconds

step-by-step explanation:

a: h(t)=1/2(-9.8)(3)^2+0(3)+90

h(t)=-4.9(3)^2+90

h(t)=-44.1+90

h(t)=45.9 meters

b: 0=1/2(-9.8)(t^2)+0t+90

0=-4.9t^2+90

-90=-4.9t^2

18.37=t^2

t=4.29 seconds

in the second question, the numbers aren't exact, but they're a close approximation.