A student investigates two solutions, C and D.
They know that:
They test 2 cm32\text{ cm}^32 cm3 of each solution for the sulfate ion using this method:
The teacher says that the student should have used a different acid instead of dilute sulfuric acid. State the name of the acid the student should have used.
Explain why using dilute sulfuric acid would affect the results of this test.
The student repeats the test for sulfate ions using the correct acid and barium chloride solution. They also test each solution using a few drops of dilute nitric acid followed by a few drops of silver nitrate solution.
The table shows their results:
| Solution | Observation with barium chloride solution | Observation with silver nitrate solution |
|---|---|---|
| C | white precipitate | no change |
| D | no change | yellow precipitate |
State the name of the anion in each solution.
Solution C also contains iron(III) ions, Fe3+\text{Fe}^{3+}Fe3+.
Iron(III) ions react with hydroxide ions, OH−\text{OH}^{-}OH−, to make a precipitate of iron(III) hydroxide.
Write the balanced ionic equation for this reaction. Include the state symbols.
Sodium chloride solutions with concentrations of 13 g/dm313\text{ g/dm}^313 g/dm3 are suitable for experiments in school.
Calculate the mass of sodium chloride that should be dissolved in 45 cm345\text{ cm}^345 cm3 of water to make a solution with a concentration of 13 g/dm313\text{ g/dm}^313 g/dm3.
Use the equation: concentration=massvolume\text{concentration} = \frac{\text{mass}}{\text{volume}}concentration=volumemass
Give your answer to 2 significant figures.