8.1 An electrochemical cell is set up using an aluminium rod, Aℓ, and a gas X.The initial emf measured under standard conditions is 2,89 V. 8.1.1 State the standard conditions under which this cell operates. (3) 8.1.2 Use a calculation to identify gas X. (5) 8.1.3 Write down the FORMULA of the reducing agent in … Read more
In the circuit below a battery of UNKNOWN emf and an internal resistance of 0,5 Ω is connected to two resistors of 4 Ω and 8 Ω each, and a resistor R of unknown resistance.Ignore the resistance of the connecting wires. 8.1 The three external resistors are ohmic conductors.Explain the meaning of the term ohmic … Read more
The table below shows two half-cells, A and B, used to assemble an electrochemicalcell under STANDARD CONDITIONS. 8.1 State the energy conversion that takes place in this cell. (1) 8.2 Calculate the mass of silver nitrate, AgNO3, used to prepare 150 cm3 of the electrolyte solution in half-cell B. (4) 8.3 Define the term reducing … Read more
Three resistors are connected to a battery with an unknown emf and unknown internalresistance r, as shown below.Ignore the resistance of the connecting wires. 8.1 In the definition of the emf of a battery given below, (a) and (b) representmissing words or phrases.The emf of the battery is the maximum (a) … supplied by a … Read more
8.1 A nickel (Ni) rod is placed in a beaker containing a silver nitrate solution, AgNO3(aq) and a reaction takes place. Write down the: 8.1.1 NAME or FORMULA of the electrolyte (1) 8.1.2 Oxidation half-reaction that takes place (2) 8.1.3 Balanced equation for the net (overall) redox reaction that takesplace (3) 8.2 A galvanic cell … Read more
Learners are given the following two unknown half-cells: Half-cell 1: Q2+ (aq) | Q(s) Half-cell 2: Pt | R2(g) | R–(aq) During an investigation to identify the two half-cells, the learners connect each half-cell alternately to a Cd2+(aq) | Cd(s) half-cell under standard conditions. For each combination of two half-cells, they write down the net … Read more
(Start on a new page.) 8.1 In the circuit below the battery has an emf (ε) of 12 V and an internal resistance of 0,2 Ω. The resistances of the connecting wires are negligible. 8.1.1 Define the term emf of a battery. (2) 8.1.2 Switch S is open. A high-resistance voltmeter is connected across points … Read more
A and B are two small spheres separated by a distance of 0,70 m. Sphere A carries a charge of +1,5 x 10-6 C and sphere B carries a charge of -2,0 x 10-6 C. P is a point between spheres A and B and is 0,40 m from sphere A, as shown in the … Read more
8.1 Learners set up a galvanic cell and measure its emf under standard conditions. 8.1.1 Write down the name of component Y. (1)8.1.2 Is Al the ANODE or the CATHODE? (1)8.1.3 Write down the overall (net) cell reaction that takes place in this cell when it is working. (3)8.1.4 Calculate the initial emf of this … Read more
Two charged particles, Q1 and Q2, are placed 0,4 m apart along a straight line. The charge on Q1 is + 2 x 10-5 C, and the charge on Q2 is – 8 x 10-6 C. Point X is 0,25 m east of Q1, as shown in the diagram below. Calculate the: 8.1 Net electric … Read more