| 2001 |
Why does a bottle of soda water fizz when it is opened? |
Chemistry
Solubility and Henry’s law |
Easy |
| 2002 |
At a given temperature, four gases have Henry's law constants (in kbar) of 0.4, 1.7, 34 and 76.5. Which gas i… |
Chemistry
Solubility and Henry’s law |
Medium |
| 2003 |
Why are the air tanks used by scuba divers diluted with helium? |
Chemistry
Solubility and Henry’s law |
Medium |
| 2004 |
The dissolution of a certain solid in water is endothermic. How will its solubility change as the temperature… |
Chemistry
Solubility and Henry’s law |
Hard |
| 2005 |
Which pair of liquids forms a nearly ideal solution? |
Chemistry
Vapour pressure and Raoult’s law |
Easy |
| 2006 |
Which statement about a solution showing negative deviation from Raoult's law is correct? |
Chemistry
Vapour pressure and Raoult’s law |
Easy |
| 2007 |
Liquids A and B form an ideal solution. p_A° = 400 mm Hg and p_B° = 200 mm Hg. What is the total vapour press… |
Chemistry
Vapour pressure and Raoult’s law |
Medium |
| 2008 |
For the solution in which p_A° = 400 mm Hg, p_B° = 200 mm Hg and x_A = 0.25, what is the mole fraction of A i… |
Chemistry
Vapour pressure and Raoult’s law |
Hard |
| 2009 |
Why can a 95% ethanol–water mixture not be made purer by simple fractional distillation? |
Chemistry
Vapour pressure and Raoult’s law |
Medium |
| 2010 |
Which of these is NOT a colligative property? |
Chemistry
Colligative properties |
Easy |
| 2011 |
What is the elevation in boiling point of a 0.5 mol kg⁻¹ aqueous solution of urea? (Kb of water = 0.52 K kg m… |
Chemistry
Colligative properties |
Easy |
| 2012 |
What is the osmotic pressure of a 0.1 M solution of a non-electrolyte at 300 K? (R = 0.0821 L atm K⁻¹ mol⁻¹) |
Chemistry
Colligative properties |
Medium |
| 2013 |
What happens to red blood cells placed in a solution with a salt concentration higher than that of blood plas… |
Chemistry
Colligative properties |
Medium |
| 2014 |
In reverse osmosis used to desalinate seawater, what must be true of the pressure applied on the seawater sid… |
Chemistry
Colligative properties |
Hard |
| 2015 |
What is the van't Hoff factor of K₂SO₄ assuming complete dissociation in water? |
Chemistry
Abnormal molar mass and van’t Hoff factor |
Easy |
| 2016 |
Ethanoic acid forms dimers in benzene. Compared with its true molar mass, the molar mass found from freezing … |
Chemistry
Abnormal molar mass and van’t Hoff factor |
Easy |
| 2017 |
What is the depression in freezing point of 0.1 mol kg⁻¹ aqueous NaCl, assuming complete dissociation? (Kf = … |
Chemistry
Abnormal molar mass and van’t Hoff factor |
Medium |
| 2018 |
Which 0.1 mol kg⁻¹ aqueous solution has the lowest freezing point? |
Chemistry
Abnormal molar mass and van’t Hoff factor |
Medium |
| 2019 |
A salt of type AB₂ dissociates partially in water and its van't Hoff factor is found to be 2.6. What is its d… |
Chemistry
Abnormal molar mass and van’t Hoff factor |
Hard |
| 2020 |
In a Daniell cell, which process takes place at the anode? |
Chemistry
Galvanic cells and electrode potential |
Easy |
| 2021 |
What is the role of a salt bridge in a galvanic cell? |
Chemistry
Galvanic cells and electrode potential |
Easy |
| 2022 |
Given E°(Zn²⁺/Zn) = −0.76 V and E°(Cu²⁺/Cu) = +0.34 V, what is the standard EMF of the Daniell cell? |
Chemistry
Galvanic cells and electrode potential |
Medium |
| 2023 |
E°(Ag⁺/Ag) = +0.80 V and E°(Cu²⁺/Cu) = +0.34 V. What happens when a copper strip is dipped into silver nitrat… |
Chemistry
Galvanic cells and electrode potential |
Medium |
| 2024 |
Which of these is the strongest reducing agent, given E° values Li⁺/Li = −3.05 V, Na⁺/Na = −2.71 V, Mg²⁺/Mg =… |
Chemistry
Galvanic cells and electrode potential |
Hard |
| 2025 |
Which relation correctly links the standard Gibbs energy change with the standard cell EMF? |
Chemistry
Nernst equation |
Easy |
| 2026 |
What is the electrode potential of a hydrogen electrode in a solution of pH 1 at 298 K, with H₂ at 1 bar? |
Chemistry
Nernst equation |
Easy |
| 2027 |
Calculate ΔG° for the Daniell cell (E°cell = 1.10 V, n = 2, F = 96500 C mol⁻¹). |
Chemistry
Nernst equation |
Medium |
| 2028 |
For the cell Zn | Zn²⁺(0.1 M) || Cu²⁺(1 M) | Cu at 298 K, with E°cell = 1.10 V, what is E_cell? |
Chemistry
Nernst equation |
Hard |
| 2029 |
A cell reaction involves 2 electrons and has E°cell = 0.2955 V at 298 K. What is its equilibrium constant? |
Chemistry
Nernst equation |
Medium |
| 2030 |
How do conductivity (κ) and molar conductivity (Λm) of an electrolyte solution change on dilution? |
Chemistry
Conductance of electrolytic solutions |
Easy |
| 2031 |
The resistance of a conductivity cell filled with 0.1 M KCl (κ = 0.0129 S cm⁻¹) is 100 Ω. What is the cell co… |
Chemistry
Conductance of electrolytic solutions |
Medium |
| 2032 |
A 0.1 M solution has conductivity 0.012 S cm⁻¹. What is its molar conductivity? |
Chemistry
Conductance of electrolytic solutions |
Easy |
| 2033 |
Given Λ°(CH₃COONa) = 91.0, Λ°(HCl) = 426.2 and Λ°(NaCl) = 126.5 S cm² mol⁻¹, what is Λ° for CH₃COOH? |
Chemistry
Conductance of electrolytic solutions |
Medium |
| 2034 |
At a certain concentration, acetic acid has Λm = 39.07 S cm² mol⁻¹ and Λ°m = 390.7 S cm² mol⁻¹. What is its d… |
Chemistry
Conductance of electrolytic solutions |
Hard |
| 2035 |
Which product forms at the cathode during electrolysis of aqueous sodium chloride with inert electrodes? |
Chemistry
Electrolysis |
Easy |
| 2036 |
How many faradays are needed to deposit 1 mol of aluminium from Al³⁺ ions? |
Chemistry
Electrolysis |
Easy |
| 2037 |
A current of 2 A is passed through CuSO₄ solution for 965 s. What mass of copper is deposited? (Cu = 63.5 g m… |
Chemistry
Electrolysis |
Medium |
| 2038 |
The same quantity of electricity that deposits 0.635 g of copper from Cu²⁺ is passed through AgNO₃ solution. … |
Chemistry
Electrolysis |
Hard |
| 2039 |
What happens at the anode when aqueous copper sulphate is electrolysed using copper electrodes? |
Chemistry
Electrolysis |
Medium |
| 2040 |
Which of these is a secondary (rechargeable) battery? |
Chemistry
Batteries, fuel cells and corrosion |
Easy |
| 2041 |
What is the overall reaction in a hydrogen–oxygen fuel cell? |
Chemistry
Batteries, fuel cells and corrosion |
Easy |
| 2042 |
Why does a mercury cell give a nearly constant voltage throughout its life? |
Chemistry
Batteries, fuel cells and corrosion |
Medium |
| 2043 |
During discharge of a lead storage battery, what is formed at both electrodes? |
Chemistry
Batteries, fuel cells and corrosion |
Medium |
| 2044 |
A scratched galvanised iron sheet still does not rust easily. What is the best explanation? |
Chemistry
Batteries, fuel cells and corrosion |
Hard |
| 2045 |
What are the usual units of the rate of a reaction in solution? |
Chemistry
Rate of reaction |
Easy |
| 2046 |
How is the instantaneous rate of a reaction found from a graph of reactant concentration against time? |
Chemistry
Rate of reaction |
Easy |
| 2047 |
In 2N₂O₅ → 4NO₂ + O₂, N₂O₅ disappears at 0.02 mol L⁻¹ s⁻¹. At what rate is NO₂ formed? |
Chemistry
Rate of reaction |
Medium |
| 2048 |
For 2HI(g) → H₂(g) + I₂(g), which expression correctly gives the rate of reaction? |
Chemistry
Rate of reaction |
Medium |
| 2049 |
Why does powdered marble react faster with dilute HCl than a single lump of the same mass? |
Chemistry
Rate of reaction |
Hard |
| 2050 |
Which statement about molecularity is correct? |
Chemistry
Rate law, order and molecularity |
Easy |