Which of the following is true for all chemical reactions?
a. the total mass of the reactants increases.
b. the total mass of the products is greater than the total mass of the reactants.
c. the total mass of the products is less than the total mass of the reactants.
d. the total mass of the reactants equals the total mass of the products.

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.