Correct answer: B
Cooling curve is the plot of temperature versus time as the sample is allowed to cool. In a cooling curve, we start at a temperature greater than the boiling point. At this temperature, the sample is in gaseous state. At the boiling point, there is no change in temperature as the gaseous and liquid states are in equilibrium. As the temperature reduces further, the liquid starts to condense and at the melting point of the sample the liquid undergoes phase transition to solid state. At the melting temperature, a second plateau is observed as the temperature remains unchanged. At temperatures below the melting point, the sample exists as a solid.
So from the curve, the second plateau is observed at around -111
. This point represents the phase transition from liquid to solid state.
Answer: 11.5 grams
Explanation:
Molarity of a solution is defined as the number of moles of solute dissolved per Liter of the solution
where,
Morality = 0.612 M
n= moles of solute
= volume of solution in ml = 100 ml
Now put all the given values in the formula of molarity, we get

Therefore, the mass of copper (II)nitrate required is 11.5 grams
Answer: Boyle's Law
Explanation:
Boyle's Law which is also called Mariotte's law was formulated by physicist Robert Boyle in 1662.
It posits that the pressure (p) of a given quantity of gas varies inversely with its volume (v) at constant temperature.
As the Scuba Diver went deeper, the volume of air dropped so the pressure increased.
Please do react or comment to the answer if you have any issues or if you feel like this helped you so we can help others as well. Thank you.