Various options are provided as possible answers to the following questions - NSC Physical Sciences - Question 1 - 2024 - Paper 2
Question 1
Various options are provided as possible answers to the following questions. Each question has only one correct answer. Choose the answer and write in the letter (A–... show full transcript
Worked Solution & Example Answer:Various options are provided as possible answers to the following questions - NSC Physical Sciences - Question 1 - 2024 - Paper 2
Step 1
1.1 The functional group for an ALDEHYDE is …
96%
114 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
The correct answer is C. carbonyl group, as aldehydes are defined by the presence of a carbonyl group (C=O) at the end of the carbon chain.
Step 2
1.2 Which ONE of the following equations represents the reaction for the IDENTIFICATION of an UNSATURATED compound in the laboratory?
99%
104 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
The correct answer is B. CH₃CH₂CH=CH₂ + Br₂ → CH₃CH₂CHBrCH₂Br. This reaction shows the addition of bromine to an alkene, confirming its unsaturation.
Step 3
1.3 Which ONE of the following is the EMPIRICAL formula of ethyl ethanoate?
96%
101 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
The correct answer is B. C₂H₄O₂. This is the simplest whole number ratio of elements in ethyl ethanoate.
Step 4
1.4 In an experiment 5 g of calcium carbonate, CaCO₃(s), reacts with EXCESS hydrochloric acid, HCl(aq), at a temperature of 40 °C. Which ONE of the curves will now be obtained?
98%
120 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
The correct answer is B. Curve II. Increasing the amount of reactant generally increases the volume of gas produced over time.
Step 5
1.5 Which statement(s) is/are TRUE when a few drops of concentrated hydrochloric acid, HCl(conc), are added to the mixture?
97%
117 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
The correct answer is B. (i) and (ii) only. Adding concentrated HCl will shift the equilibrium to the left, increasing Cr₂O₇²⁻ concentration and maintaining the color change.
Step 6
1.6 If the equilibrium constant Kc = 1 x 10⁴, then …
97%
121 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
The correct answer is C. [A] > [C][D]. Since Kc is large, the concentration of products is greater than that of reactants at equilibrium.
Step 7
1.7 Which ONE of the following shows the PRODUCTS for the reaction of oxalic acid with sodium hydroxide?
96%
114 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
The correct answer is A. (COO)₂Na₂(aq) + H₂O(l) + CO₂(g). This represents the neutralization of oxalic acid by sodium hydroxide.
Step 8
1.8 Which ONE of the following Kₐ values represents the WEAKEST acid at 25 °C?
99%
104 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
The correct answer is C. 1.8 x 10². The smaller the Kₐ, the weaker the acid.
Step 9
1.9 Which ONE of the following combinations is CORRECT for the changes occurring at the anode, cathode and in the electrolyte when the cell is in operation?
96%
101 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
The correct answer is B. Decreases. The mass of the anode decreases as copper ions are oxidized and deposited at the cathode, which increases in mass.
Step 10
1.10 Which ONE of the following redox reactions is SPONTANEOUS under standard conditions?
98%
120 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
The correct answer is D. Cu + Pb²⁺ → Cu²⁺ + Pb. This reaction is spontaneous as it results in the reduction of lead ions.
