A solution has a pH of 4. After diluting it 100 times with water, what is the approximate pH? (pH is the negative log (base 10) of the concentration of hydrogen ions, measured in mol/dm³)
Xinyi prepares a solution with pH 3 and then dilutes it by adding 90 cm³ of water to 10 cm³ of the solution. What is the expected final pH (assuming ideal dilution)? (pH is the negative log (base 10) of the concentration of hydrogen ions, measured in mol/dm³)
Xinyi is learning about the differences between acids and alkalis in school. Which ion is characteristic for all acidic solutions?
Which of the following salts is *not* commonly prepared by the titration method?
John adds excess zinc granules to 20 cm³ of dilute sulphuric acid and notices bubbles forming. Which of the following would increase the rate of reaction?
John decides to write a balanced chemical equation for ammonia production but messes up. Which is the correct balanced equation for the Haber process?