Question

2 A student wishes to check the upper and the lower fixed points on a Celsius scale thermometer. -10 0 10 20 30 40 50 60 70 80 90 100 110 °C She has four beakers P, Q, R and S. Beaker P contains a mixture of ice and salt. Beaker Q contains a mixture of ice and water. Beaker R contains boiling salt solution. Beaker S contains boiling water. Which two beakers should she use to check the fixed points? AP and R B P and S C Q and R D Q and S​

Answer 1

To verify the upper and lower fixed points on a Celsius thermometer, beakers Q (ice and water) and S (boiling water) should be used to check 0°C and 100°C respectively. The correct option is D.

Step-by-step explanation:

To check the upper and lower fixed points on a Celsius scale thermometer, the student should use beakers Q and S. Beaker Q, which contains a mixture of ice and water, will be used to check the lower fixed point of 0°C, because at this temperature, ice and water coexist in equilibrium.

Beaker S, which contains boiling water, will be used to check the upper fixed point of 100°C, which is the boiling point of water at standard atmospheric pressure. Thus, the correct answer is D, beakers Q and S.