Question

Josh is making homemade lollipops. the recipe calls for dissolving 400 g sugar in 100 g of water. his friend, alex, said that would never work because sugar's solubility is 204 g per 100 g of water at 20°c. despite alex's doubts, josh successfully dissolves all 400 g of the sugar. what did josh do that allowed him to dissolve that much sugar in only 100 g of water? josh used sugar cubes instead of granulated sugar. josh used a pan with a large surface area. josh stirred the solution. josh heated the water.

Answer 1

The correct answer is "josh heated the water."

The solubility of sugar is 204 g per 100 g of water only at 20°C. The solubility of sugar increases with increase in temperature. At high temperatures the kinetic energy of water molecule increases which can now effectively break apart the sugar molecules that are held together by intermolecular forces of attraction.

Thus 400 g of the sugar will dissolve in water at a temperature higher than 20°C.