A scientist investigates how fast four different solid pellets dissolve in an acidic solution. Each pellet has a different surface area. They add each pellet to 50 cm3 of dilute acid and measure the time taken for it to completely dissolve. The table shows their results:
| Pellet | Surface area of pellet (cm2\text{cm}^2cm2) | Volume of pellet (cm3\text{cm}^3cm3) | Surface area to volume ratio | Time taken to dissolve (seconds) |
|---|---|---|---|---|
| P | 3.6 | 0.4 | 9.0 : 1 | 48 |
| Q | 2.2 | 0.2 | 11.0 : 1 | 39 |
| R | 1.4 | 0.2 | 61 | |
| S | 4.8 | 0.3 | 16.0 : 1 |
Calculate the surface area to volume ratio of pellet R.
A scientist investigates how fast four different solid pellets dissolve in an acidic solution. Each pellet has a different surface area. They add each pellet to 50 cm3 of dilute acid and measure the time taken for it to completely dissolve. The table shows their results:
| Pellet | Surface area of pellet (cm2\text{cm}^2cm2) | Volume of pellet (cm3\text{cm}^3cm3) | Surface area to volume ratio | Time taken to dissolve (seconds) |
|---|---|---|---|---|
| P | 3.6 | 0.4 | 9.0 : 1 | 48 |
| Q | 2.2 | 0.2 | 11.0 : 1 | 39 |
| R | 1.4 | 0.2 | 61 | |
| S | 4.8 | 0.3 | 16.0 : 1 |
Complete the sentence to describe the relationship between the surface area to volume ratio and the time taken to dissolve: "As the surface area to volume ratio increases, the pellet will take ______________ time to dissolve."
A scientist investigates how fast four different solid pellets dissolve in an acidic solution. Each pellet has a different surface area. They add each pellet to 50 cm3 of dilute acid and measure the time taken for it to completely dissolve. The table shows their results:
| Pellet | Surface area of pellet (cm2\text{cm}^2cm2) | Volume of pellet (cm3\text{cm}^3cm3) | Surface area to volume ratio | Time taken to dissolve (seconds) |
|---|---|---|---|---|
| P | 3.6 | 0.4 | 9.0 : 1 | 48 |
| Q | 2.2 | 0.2 | 11.0 : 1 | 39 |
| R | 1.4 | 0.2 | 61 | |
| S | 4.8 | 0.3 | 16.0 : 1 |
The scientist thinks that pellet S will take the longest time to dissolve (dissolve slowest) in the acid. Explain why the scientist is incorrect.
The scientist performs thin-layer chromatography (TLC) on a solution containing a chemical from pellet P.
The spots on the resulting chromatogram are colourless. State what the scientist could use to see the spots.
The scientist performs thin-layer chromatography (TLC) on a solution containing a chemical from pellet P.
After using a technique to visualize the spots, the chromatogram for Pellet P is shown below:
Calculate the Rf R_f\,Rf value for the spot seen from Pellet P. Show your working.