Suppose now that you wanted to determine the density of a small crystal to confirm that it is boron. From the literature, you know that boron has a density of 2.34 g/cm^3. How would you prepare 20.0 mL of the liquid mixture having that density from pure samples of CHCI3 ( d= 1.492 g/mL) and CHBr3( d= 2.890 g/mL)? (Note: 1 mL = 1 cm^3.)

i'm assuming that the correct answer is indeed the first one/ "a"..

"standard molar enthalpy:

h2o ( liquid water ) : - 285.8 kj/mole

h2o ( water vapor ) : - 241.8 kj / mole.

δhrxn = - 241. 8 - ( - 285.8 )= -241.8 + 285.8 = 44.0

answer: 44.0 kj"

i have no clue hope you find the answer

definition

                    entropy is a measure of the randomness or the extent of disorder of a chemical process.

                      enthalpy is a measure of the heat change of a reaction occurring at a constant pressure.

measurement units:

                        entropy is measured in joule per kelvin (jk⁻¹)   whereas enthalpy is measured in joule per mole (jmol⁻¹)

requirements:

                            entropy has no requirements or limits, and its change is measured by the division between the heat change of the chemical process and the temperature.

                              in contrast, enthalpy can only be related to the heat change of the reaction under standard conditions.