| Product/Dilution
|
Time (Mins)
|
Observations
|
| Phosphoric acid 1%
|
1
|
little to no bubbles or foam, no color change in solution or marble, marble looks the same
|
| 5
|
Tiny bubbles are covering the entire surface of the marble, no color change in solution or marble
|
| 10
|
no change from previous observations
|
| 15
|
no change from previous observations
|
| 30
|
no change from previous observations
|
| FB 1000 10%
|
1
|
little bubbles, foaming, rising slowly, no color change or pieces breaking off, marble looks same
|
| 5
|
lighter color change, cloudy white liquid, all other observations the same
|
| 10
|
more cloudy white at bottom of beaker, crack forming on marble (side corner), no other changes
|
| 15
|
marble turning slight whiter in color, bubble rate slowing, another crack down middle of marble, no other changes
|
| 30
|
solution cloudier, marble got more pale in color, all other observations are the same
|
| FB 1000 2%
|
1
|
little to no bubbles or foaming, no color change or pieces falling off, marble looks the same
|
| 5
|
no change from previous observations
|
| 10
|
no change from previous observations
|
| 15
|
some cloudy whitening of solution at the bottom near the marble, no other changes
|
| 30
|
no change from previous observation
|
| FB 1000 1%
|
1
|
little to no bubbles or foam, no color change, marble looks the same
|
| 5
|
no change from previous observation
|
| 10
|
no change from previous observation
|
| 15
|
no change from previous observation
|
| 30
|
no change from previous observation
|
The FB-1000 10% caused faster degradation of the marble's surface compared to the phosphoric acid 1% solution and appeared paler after immersing for 30 minutes and with a rinse in DI water. FB-1000 2% dilution outperformed the 1% phosphoric acid solution in degrading calcium and the overall percent removed from the marble block. The FB-1000 1% was effective and removed slightly more calcium (in grams) from the block than the phosphoric acid 1% solution, although its overall percentage removal was half that of the phosphoric acid solution.