6 Pressure affects the boiling point Put water in a sidearm testtube or in a roundbottom flask with a 2hole stopper Insert a thermometer through a hole in the stopper so that the bulb of the thermometer reaches but does not touch the bottom of the testtube or flask Add boiling chips to prevent bumping Boil the water and read the temperature on the thermometer Stop heating Connect a water pump to the sidearm or to the second hole of the 2hole stopper When the water stops boiling turn on the water pump to reduce the pressure Read the temperature heat to boiling and read the temperature again