Exam-style multiple choice and written questions with full markschemes. Check multiple choice answers straight away, or type, photograph or draw a written answer and get it marked.
A student uses a calibrated pH meter to measure an aqueous ethanoic acid solution. Figure 1 shows the meter reading.
State the pH of the solution shown in Figure 1.
Calculate the hydrogen ion concentration, [H⁺], in the solution. Give your answer in mol dm⁻³ to two significant figures.
At room temperature, of magnesium ribbon is added to excess dilute hydrochloric acid. Figure 1 shows the measured volume of gas collected over time.
Use Figure 1 to state the volume of gas collected after
Write a balanced equation, including state symbols, for the reaction of magnesium with dilute hydrochloric acid.
In a voltaic cell, electrode A undergoes the reaction
Identify electrode A as the anode or cathode and state its sign.
In an electrolytic cell, electrode B undergoes the reaction
Identify electrode B as the anode or cathode and state its sign.
Ethane reacts with bromine under ultraviolet light. Bromoethane is one product, and the reaction proceeds by a radical chain mechanism.
Write the two propagation equations for the reaction of ethane with bromine.
Write a termination equation involving two ethyl radicals.
State one reason why a mixture of organic products can form.
State two features of alkanes that contribute to their low reactivity.
In a reaction mechanism for bromomethane, a curly arrow starts at the C–Br bond and points to Br. Which equation represents the products of this bond cleavage?
Answer: C. The curly arrow from the bond to Br shows the bonding electron pair moving to Br. Carbon loses its share of the pair, giving CH₃⁺; bromine gains both electrons, giving Br⁻.
A: splits the pair between the fragments, producing radicals by homolytic fission.
B: reverses the electron-pair movement, assigning both electrons to carbon.
D: represents cleavage of a C–H bond rather than the specified C–Br bond.
Remember: a curly arrow from a bond to an atom shows that the bonding pair moves to that atom.
Unlock every question in this topic, then type, photograph or draw your answer and have it marked against the markscheme. Find out where you are dropping marks.