0620/63 · May/June 2023
Download PDFThis question is about separating mixtures.
Name the separation technique that uses the apparatus shown in Fig. 1.1.
Name the items of apparatus labelled A and B. A ......................................................................................................................................... B .........................................................................................................................................
Draw an arrow on Fig. 1.1 to show where the apparatus should be heated.
State the term used for the solid removed from a liquid using the apparatus shown in Fig. 1.2.
The calcium carbonate obtained using the apparatus in Fig. 1.2 is contaminated with aqueous sodium chloride. Describe how the aqueous sodium chloride can be removed.
Name the method of separation that can be used to obtain solid sodium chloride from an aqueous solution of sodium chloride.
A student investigates the temperature change when solid citric acid reacts with solid sodium carbonate. The student does six experiments.
Use the information in the description of the experiments and the thermometer diagrams to complete Table 2.1.
Complete a suitable scale on the y-axis and plot the results from Experiments 1 to 6 on Fig. 2.1. Draw a line of best fit through your points.
State whether the reaction between solid sodium carbonate and solid citric acid is exothermic or endothermic. Explain your answer.
Deduce which experiment had the greatest temperature change compared to the temperature in Experiment 1.
From your graph, deduce the temperature, after stirring for 30 seconds, that is obtained when 3.5 g of solid citric acid is added to 5.0 g of solid sodium carbonate. Show clearly on the grid how you worked out your answer. temperature = .............................. °C
Suggest why the solid sodium carbonate and solid citric acid are stirred before the temperature is measured.
Explain why using a polystyrene cup in place of the glass beaker would increase the accuracy of the results.
A student tests two solids: solid G and solid H. Tests on solid G Table 3.1 shows the student’s observations for solid G. Solid G contains three ions.
State what conclusion can be made about solid G from the observations in test 2.
State what conclusion can be made about solid G from the observations in test 4.
The observations in test 3 show that one of two possible cations could be in solid G. Identify these two possible cations.
Identify two ions, other than those you gave in (c), which must be in solid G.
About 10 cm of dilute hydrochloric acid is added to solid H. Any gas given off is tested. observations ..............................................................................................................................
To the first portion of solution I, add aqueous sodium hydroxide dropwise and then in excess. observations when added dropwise .......................................................................................... observations in excess ..............................................................................................................
To the second portion of solution I, add 1 cm of dilute nitric acid followed by a few drops of aqueous silver nitrate. observations ..............................................................................................................................
Oxalic acid is a white solid which is soluble in both water and ethanol to form colourless solutions. Plan an experiment to determine if oxalic acid is more soluble in water or in ethanol, at room temperature. Your answer should include how your results tell you if oxalic acid is more soluble in water or in ethanol, at room temperature. You are provided with oxalic acid, water, ethanol and common laboratory apparatus.