I just did an experiment on this actually.
Water molecules travel faster in hot water than in cold water. When food dye is added into hot water where the molecules are traveling faster, it mixes faster. In cold water, the particles are not traveling as fast and the food dye does not spread as fast.
Powdered juice dissolves faster in hot water, but tastes better in cold water.
coffee
salt dissolve faster in hot water
Sugar.
Somewhat, but it dissolves faster in warm water.
yes
Probably hot water.
Sugar dissolves faster in hot water, because the water molecules move about faster when they are hot so, when you pour in sugar, the water mollecules will collide with the sugar and theredore sugar dissolves faster in hot water.
Hot water mixes with food coloring faster than cold water. The heat increases the speed of molecular movement, allowing the food coloring to disperse quicker and more thoroughly.
Warm Water! when molecules inside of an object heat up, the molecules go faster! which will absorbe the food coloring faster.
salt
hot water