What is the fastest way to dissolve a sugar cube in what liquid?

The fastest way to dissolve a sugar cube in a liquid is by using hot water. When water is heated, the molecules move faster and have more energy, allowing them to break down the sugar cube more quickly. The increased temperature also decreases the solubility of the sugar, further aiding in its dissolution. Stirring the solution will also help to speed up the process by distributing the sugar molecules more evenly throughout the liquid.