Answer : The molar mass of unknown substance is, 39.7 g/mol
Explanation : Given,
Mass of unknown substance = 9.56 g
Volume of solution = 100.0 mL
Molarity = 2.41 M
Molarity : It is defined as the number of moles of solute present in one liter of volume of solution.
Formula used :

Now put all the given values in this formula, we get:


Therefore, the molar mass of unknown substance is, 39.7 g/mol
2.B. Describe the difference between a reaction that occurs spontaneously and one that does not. Spontaneous chemical reactions release energy and use that energy to power itself; non-spontaneous chemical reactions need to absorb energy, which they can't absorb their own energy that they don't even have.
Answer:
"A", "water changes from a gas to a solid to a liquid", according to this phase diagram, at at 0°C, as pressure is increased from 0atm to 10atm.
Explanation:
The question asks what happens at 0°C, as pressure is increased from 0atm to 10atm.
According to the question, the temperature is held constant. The pressure changes. In the phase diagram, we find the temperature 0°C on the horizontal axis, and all points where the temperature are 0°C are along that vertical line.
Since the pressure starts at 0atm and increases to 10atm, we start at the bottom, and move upward along that line, to see what phases of matter the substance changes to.
At the bottom, it is initially in a "gas" phase. As it moves up, it transitions to a "solid" phase. Later, as it continues moving up, it changes again into a "liquid" phase.
Thus, the answer would be "A", "water changes from a gas to a solid to a liquid", according to this phase diagram, at at 0°C, as pressure is increased from 0atm to 10atm.
A homogenous mixture is uniform and thus hard to recognize as a mixture. An example is water!