Practice 10 questions on CHEM120 - General Chemistry at Durban University of Technology. Free AI-generated quiz on uNotes — track your score, retake anytime.
1A 300 g block of aluminum is heated from 20°C to 100°C. If the specific heat capacity of aluminum is 0.897 J/g°C, how much heat energy is absorbed by the block?
2For a specific chemical reaction, the enthalpy change (ΔH) is -30 kJ/mol and the entropy change (ΔS) is -80 J/mol·K. At what temperature range will this reaction be spontaneous?
3The decomposition of hydrogen peroxide is a first-order reaction with a rate constant of 1.2 x 10^-3 s^-1. If the initial concentration is 0.84 M, what is the concentration after 2000 seconds?
4Calculate the rate of reaction for: A + B -> C, given it is second-order with respect to A and first-order with respect to B, with a rate constant k = 1.0 L²/mol²·s, [A] = 0.01 M, and [B] = 0.02 M.
5Determine the standard cell potential (E°cell) for a galvanic cell consisting of a silver electrode (E°red = +0.80 V) and a copper electrode (E°red = +0.34 V).
6Using Faraday's law, calculate the mass of silver (Ag) plated out of an AgNO3 solution by a current of 2.0 A flowing for 10 minutes. (Atomic weight of Ag = 107.87 g/mol, F = 96485 C/mol)
7A solution is prepared by mixing 100 g of water (MW = 18 g/mol) and 100 g of ethanol (MW = 46 g/mol). What is the mole fraction of ethanol in this solution?
8For the equilibrium reaction N2(g) + 3H2(g) ⇌ 2NH3(g), the equilibrium concentrations are [N2] = 0.1 M, [H2] = 0.3 M, and [NH3] = 0.8 M. Calculate the value of Kc.
9Calculate the pH of a buffer solution containing 0.25 M acetic acid (CH3COOH) and 0.15 M sodium acetate (CH3COONa). (Ka for acetic acid = 1.8 x 10^-5)
10The solubility product constant (Ksp) for silver chloride (AgCl) is 1.6 x 10^-10 at 25°C. What is the molar solubility of AgCl in pure water?
