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.
That statement is true because to make a diluted solution, you have to add more solvent than the solute in a concentrated solution. This is extra information, but to make a diluted solution more concentrated, you have to add more solute since a concentrated solution has an excess amount of solute as stated before.
The coronavirus is a respiratory illness (like the flu) with symptoms such as a cough, fever, and in more severe cases, difficulty breathing. you can prevent this illness by washing your hands frequently, avoiding touching your face, and avoiding close contact with people who are sick.
The only exception of calculating mechanical advantage is by multiplying resistance force by effort force. For example, in calculating the mechanical advantage of a lever, we consider its output and input forces. The equation would now be as follows:
Mechanical advantage = output force / input force