Question

A solution of hydrochloric acid is placed on a balance. Magnesium metal is added and the mass is recorded. The solution is stirred and the mass of the solution is recorded every 10 minutes. The following data is collected:

Time (mins) Mass of Hydrochloric Acid and Magnesium (g)
0 160.0 g
10 156.5 g
20 152.0 g
30 147.5 g
40 142.5 g
What does the data show is occurring?
The hydrochloric acid and magnesium metal react to form a soluble compound.
The hydrochloric acid and magnesium metal do not react.
The hydrochloric acid and magnesium metal react to form a precipitate.
The hydrochloric acid and magnesium metal react to form a gas.

Answer 1

The hydrochloric acid and magnesium metal react to form a gas.

Step-by-step explanation:

i got it on study island

Answer 2

Remember conservation of mass. Mass can't just suddenly show up or disappear. It has to come from somewhere, and it has to go somewhere.

The mass of this mixture/solution is decreasing as time goes on. That
means that some mass is going somewhere, out of the dish and away
off the scale.

-- React to form a soluble compound ?
Maybe, but that doesn't take mass away

-- They don't react ?
Maybe, but that doesn't take mass away

-- React to form a precipitate ?
Maybe, so big deal. It sinks to the bottom. It doesn't take mass away.

-- React to form a gas ?
If that happens, then the gas carries mass away !
That must be it !