Please, I need help with this badly: Substance A has a normal melting point of -25.0 °C, an enthalpy of fusion of 1200 J g'; specific
heat for the solid is 3.00 Jg'c and the liquid is 6.20 J g''C'' Determine the heat needed to
change 150 grams of A from a solid at - 40.0 °C to a liquid at +70.0°c. Draw the diagram to
illustrate the process that is occurring.

Which characteristic of water it form droplets? a. low specific heat b. nonpolar structure c. high surface tension d. ability to dissolve substances

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.

Anthracite is so hard and pure it is also referred to as a renewable resource metamorphic rock hot bituminous coal dirty fuel