How much does an egg weigh in 5 percent Na Cl solution?

Answer 1

Placing the egg in any concentration of salt water will not immediately change its weight. It will remain as heavy as when it was dry. That is to say, gravity will pull it downward just as hard. Once in the water, the displaced water will push it up against the downward force of gravity and it will become buoyant. If the volume of the egg is greater than the displaced water, it will float.

An egg will likely float in five percent NaCl solution because it is denser than the liquid portion of the egg but the question cannot be accurately answered without knowing the density of the intact egg. A very fresh egg is more completely full but an old egg has lost moisture through the shell and the air pocket at the broad end has increased.

You will need to measure the volume of the egg and get its mass. If the mass divided by the volume of the egg is less than 1.032465 grams/ml (interpolated from data at 20 C in Salt Institute table--see link) the egg will float.

Over time, the egg will become more buoyant because the salt solution is hypertonic to the liquid in the egg and it can be expected that water will move across the membrane (shell) and air will move into the egg from the surface exposed to the air. If the egg started fully submerged it is likely that osmosis will reach equilibrium at some point before the egg shell cracks from the pressure differential. As the moisture is lost by osmosis, the weight of the egg will decrease (slightly) but the amount of that weight loss can be determined only by experimentation.

Answer 2

An egg will weigh less in a 5 percent NaCl solution due to the lower density of the solution compared to water. The weight loss will depend on the volume of the egg and the specific gravity of the solution.