Atheelah Arendse

The simplified diagram below represents an electrochemical cell used for the electrolysis of a concentrated sodium chloride solution, NaCℓ(aq). X and Y are carbon electrodes. 9.1 Define the term electrolysis. (2) 9.2 Chlorine gas, Cℓ2(g), is released at electrode X. Write down the:9.2.1 Letter (X or Y) of the electrode where oxidation takes place (1) … Read more

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

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

6.1 Initially, 4 moles H2(g) and 4 moles I2(g) are allowed to react in a sealed2 dm3 flask according to the following balanced equation: H2(g) + I2(g) ⇌ 2HI(g) ΔH < 0 The graph below shows the concentrations of H2(g) and HI(g) versus time during the reaction.

Learners use the reaction of MgCO3(s) with EXCESS dilute HCℓ(aq) to investigate therelationship between temperature and the rate of a chemical reaction.The balanced equation for the reaction is:MgCO3(s) + 2HCℓ(aq) → MgCℓ2(aq) + CO2(g) + H2O(ℓ)The results obtained are represented in the graph below. 5.1 Define the term rate of reaction. (2) 5.2 State TWO … Read more

4.1 Study the following incomplete equations for organic reactions I and II.Compounds P and Q are ORGANIC compounds and T is an INORGANIC compound. For reaction I, write down the:4.1.1 Type of reaction that takes place (1) 4.1.2 IUPAC name of compound P (2)4.1.3 NAME or FORMULA of compound T (1) For reaction II, write … Read more

Learners investigate factors that influence the boiling points of organic compounds.The boiling points of some organic compounds obtained are shown in the table below. 3.1 Define the term boiling point. (2) 3.2 The boiling points of compounds A, B and C are compared.3.2.1 How do the boiling points vary from compound A to compound C?Choose … Read more

The letters A to H in the table below represent eight organic compounds. 2.1 Write down the LETTER that represents a compound that:2.1.1 Is a ketone (1) 2.1.2 Has the general formula CnH2n-2 (1) 2.1.3 Is an isomer of 2-methylbut-2-ene (1) 2.1.4 Has the same molecular formula as ethyl ethanoate (1) 2.2 Write down the:2.2.1 … Read more

1.1 Which ONE of the following compounds has the LOWEST melting point?A. HexaneB. EthaneC. ButaneD. Octane (2) 1.2 When CH2 = CH2 is converted to CH3CH3, the type of reaction is …A. hydration.B. hydrolysis.C. halogenation.D. hydrogenation. (2) 1.3 Which ONE of the following compounds in solution will change the colour ofbromothymol blue?A. CH3CH2CHOB. CH3CH2COOHC. CH3CH2COCH3D. … Read more