A student made a solution of potassium hydroxide by dissolving 14.0 g14.0\text{ g}14.0 g of solid potassium hydroxide in distilled water to make 200 cm3200\text{ cm}^3200 cm3 of solution.
Calculate the amount, in moles, of KOH\text{KOH}KOH in 14.0 g14.0\text{ g}14.0 g of potassium hydroxide. (Relative atomic masses: K=39\text{K} = 39K=39, O=16\text{O} = 16O=16, H=1\text{H} = 1H=1)
Calculate the concentration, in mol/dm3\text{mol/dm}^3mol/dm3, of this solution of potassium hydroxide.
The student uses the potassium hydroxide solution to find the concentration of a solution of nitric acid. He uses this method:
The diagram shows his burette readings.
Complete the table, giving all values to the nearest 0.05 cm30.05\text{ cm}^30.05 cm3.
| Measured Parameter | Volume (cm3\text{cm}^3cm3) |
|---|---|
| burette reading at end in cm3\text{cm}^3cm3 | |
| burette reading at start in cm3\text{cm}^3cm3 | |
| volume of acid added in cm3\text{cm}^3cm3 |
State the colour of the phenolphthalein at the start and at the end of the experiment.
Why is a burette used instead of a pipette for adding the acid?
Potassium hydroxide reacts with carbon dioxide.
The equation for this reaction is
2KOH+CO2→K2CO3+H2O 2\text{KOH} + \text{CO}_2 \rightarrow \text{K}_2\text{CO}_3 + \text{H}_2\text{O} 2KOH+CO2→K2CO3+H2OA solution of potassium hydroxide of concentration 1.60 mol/dm31.60\text{ mol/dm}^31.60 mol/dm3 is used.
Calculate the amount, in moles, of potassium hydroxide in 300 cm3300\text{ cm}^3300 cm3 of this solution.
Deduce the maximum mass, in grams, of carbon dioxide that can react with this solution of potassium hydroxide. (Relative formula mass: CO2=44\text{CO}_2 = 44CO2=44)
