Seems like it's a well-known fact that adding salt to water will not raise the water volume by much (e.g.: Why there is no change in water level when salt is added? )

I've done this experiment at home and saw unexpected results:

Setup:

1. Start with 500 ml of tap water in measuring cup (500 grams)
2. Measure 50 ml of iodized salt in measuring cup (80 grams)
3. Add salt to water, stir until dissolved

Result: around 540 ml (give or take) of salt water in measuring cup weighing 580 grams

Weight was measured with kitchen scale, volume measure by eye, but ~40 ml increase in total volume seems way too much.

Followed up by replacing salt with sand, volume went up by about the same amount.

What am I missing here?

p.s.: the commenter pointed out that my salt volume is off, I should have looked up the density to go by weight rather than by measuring cup notches. Going by weight, I've added 37 ml or salt, making the result event closer. Volumes were judged by eye in food measuring cups, not exactly the proper lab equipment.

Seems like it's a well-known fact that adding salt to water will not raise the water volume by much (e.g.: Why there is no change in water level when salt is added? )

I've done this experiment at home and saw unexpected results:

Setup:

1. Start with 500 ml of tap water in measuring cup (500 grams)
2. Measure 50 ml of iodized salt in measuring cup (80 grams)
3. Add salt to water, stir until dissolved

Result: around 540 ml (give or take) of salt water in measuring cup weighing 580 grams

Weight was measured with kitchen scale, volume measure by eye, but ~40 ml increase in total volume seems way too much.

Followed up by replacing salt with sand, volume went up by about the same amount.

Video: https://www.youtube.com/watch?v=rLTn5jKqipU

What am I missing here?

p.s.: the commenter pointed out that my salt volume is off, I should have looked up the density to go by weight rather than by measuring cup notches. Going by weight, I've added 37 ml or salt, making the result event closer. Volumes were judged by eye in food measuring cups, not exactly the proper lab equipment.

Seems like it's a well-known fact that adding salt to water will not raise the water volume by much (e.g.: Why there is no change in water level when salt is added? )

I've done this experiment at home and saw unexpected results:

Setup:

1. Start with 500 ml of tap water in measuring cup (500 grams)
2. Measure 50 ml of iodized salt in measuring cup (80 grams)
3. Add salt to water, stir until dissolved

Result: around 540 ml (give or take) of salt water in measuring cup weighing 580 grams

Weight was measured with kitchen scale, volume measure by eye, but ~40 ml increase in total volume seems way too much.

Followed up by replacing salt with sand, volume went up by about the same amount.

What am I missing here?

Seems like it's a well-known fact that adding salt to water will not raise the water volume by much (e.g.: Why there is no change in water level when salt is added? )

I've done this experiment at home and saw unexpected results:

Setup:

1. Start with 500 ml of tap water in measuring cup (500 grams)
2. Measure 50 ml of iodized salt in measuring cup (80 grams)
3. Add salt to water, stir until dissolved

Result: around 540 ml (give or take) of salt water in measuring cup weighing 580 grams

Weight was measured with kitchen scale, volume measure by eye, but ~40 ml increase in total volume seems way too much.

Followed up by replacing salt with sand, volume went up by about the same amount.

What am I missing here?

p.s.: the commenter pointed out that my salt volume is off, I should have looked up the density to go by weight rather than by measuring cup notches. Going by weight, I've added 37 ml or salt, making the result event closer. Volumes were judged by eye in food measuring cups, not exactly the proper lab equipment.