A student starts with a beaker containing a solution of sodium hydroxide. They gradually add an excess of dilute hydrochloric acid while monitoring the pH.
Which of the following is the most likely change in pH during the experiment?
from 141414 to 111
from 111 to 141414
from 141414 to 777
from 777 to 111
276 exam-style questions on Edexcel GCSE Chemistry 4.1 Acids, covering 4.1.1 Acids, alkalis and the pH scale, 4.1.2 Hydrogen ion concentration and pH, 4.1.3 Dilute and concentrated, weak and strong acids, 4.1.4 Bases, alkalis and the reactions of acids, 4.1.5 Chemical tests for hydrogen and carbon dioxide, 4.1.6 Neutralisation as a reaction of acids with bases, 4.1.7 Preparing soluble salts, and 4.1.8 Solubility rules and preparing insoluble salts. Each one has a worked solution and a mark scheme showing where the marks go.