7.1 Two acids, HX and HY, of EQUAL CONCENTRATIONS are compared.The pH of HX is 2,7 and the pH of HY is 0,7. 7.1.1 Define an acid in terms of the Lowry-Brønsted theory. (2) 7.1.2 Which acid, HX or HY, is STRONGER? Give a reason for the answer. (2) 7.1.3 Acid HX ionises in water … Read more
7.1 Two small, identical spheres, P and T, are placed a distance of 0,1 m apart, B as shown in the diagram below. P carries a charge of +3 x 10-6 C and T carries a charge of -3 x 10-6 C. 7.1.1 State Coulomb’s law in words. (2) 7.1.2 Draw the resultant electric field … Read more
Learners prepare a solution of known concentration by dissolving 2 g pure sodium hydroxide crystals, NaOH, in water in a 250 cm3 volumetric flask.7.1 Write down the term for the underlined phrase. (1) 7.2 Calculate the:7.2.1 Concentration of the sodium hydroxide solution (4) 7.2.2 pH of the solution (4) The learners now react 1,5 g … Read more
Two charged spheres, R and S, are both stationary on a smooth, insulated surfaceinclined at an angle of 25° to the horizontal. Sphere S, of mass 0,01 kg and carrying acharge of –6 x 10-9 C, is connected to a 0,03 m long, light inextensible string attachedto point P at the top of the incline.Sphere … Read more
7.1 A learner dissolves ammonium chloride (NH4Cℓ) crystals in water and measures the pH of the solution. 7.1.1 Define the term hydrolysis of a salt. (2) 7.1.2 Will the pH of the solution be GREATER THAN, SMALLER THAN or EQUAL TO 7? Write a relevant equation to support your answer. (3) 7.2 A sulphuric acid … Read more
SECTION D: POETRY In this section there are questions set on the following poems: • ‘Death be not proud’ by John Donne• ‘A prayer for all my countrymen’ by Guy Butler NOTE: Answer the questions set on BOTH poems, i.e. QUESTION 7.1 AND QUESTION 7.2. QUESTION 7 7.1 Read the poem carefully and then answer … Read more
7.1 Ammonium chloride crystals, NH4Cl(s), dissolve in water to form ammonium and chloride ions. The ammonium ions react with water according to the balanced equation below: 7.1.1 Write down the name of the process described by the underlined sentence. (1) 7.1.2 Is ammonium chloride ACIDIC or BASIC in aqueous solution? Give a reason for the … Read more
(Start on a new page.) 7.1 In an experiment to verify the relationship between the electrostatic force, FE, and distance, r, between two identical, positively charged spheres, the graph below was obtained. 7.1.1 State Coulomb’s law in words. (2) 7.1.2 Write down the dependent variable of the experiment. (1) 7.1.3 What relationship between the electrostatic … Read more
Two small spheres, X and Y, carrying charges of +6 x 10-6 C and +8 x 10-6 C respectively, are placed 0,20 m apart in air. 7.1 State Coulomb’s law in words. (2) 7.2 Calculate the magnitude of the electrostatic force experienced by charged sphere X. (4) A third sphere, Z, of unknown negative charge, … Read more