Can i have will give 60 points to the correct answer and i will also mark brainlest! if it's not to much to ask, also a explanation! : ) in advance! : )
which equation is balanced?
2na + cl2→nacl

na + cl2→nacl

2na + cl2→2nacl

na + 2cl2→2nacl

This is a mixture that has the same composition throughout.

Lab reagent, hypothesis test. a reference solution used as a lab reagent is purported to have a concentration of 5 mg/dl. six samples are taken from this solution and the following concentrations are recorded: (5.32, 4.88, 5.10, 4.73, 5.15, 4.75) mg/dl. these six measurements are assumed to be an srs of all possible measurements from solution. they are also assumed to have a standard deviation of 0.2, a normal distributin, and a mean concentration equal to the true concentration of the solution. carry out a significance test to determine whether these six measurements provide reliable evidence that the true concentration of the solution is actually not 5 mg/dl.

How many moles of bromine are needed to produce 3.23 moles of potassium bromide