sentence: Potassium nitrate needs to be very hot before it melts.
sentences_before: First, the potassium nitrate is ground or milled. It needs to be made into a powder. Then the potassium nitrate is mixed with powdered sugar in a pot. When the heat is turned on, the sugar melts. However, this method does not actually melt the potassium nitrate.
sentences_after: Its melting temperature is 613 degrees Fahrenheit. So instead of melting, the grains of potassium nitrate are coated with the melted sugar.
concept_name: potassium nitrate
headings: Rocket candy Preparation
categories: Fuel Rockets