| 2051 |
The rate constant of a reaction has units of s⁻¹. What is the order of the reaction? |
Chemistry
Rate law, order and molecularity |
Easy |
| 2052 |
For 2NO + O₂ → 2NO₂, rate = k[NO]²[O₂]. By what factor does the rate change if [NO] is doubled while [O₂] is … |
Chemistry
Rate law, order and molecularity |
Medium |
| 2053 |
For a reaction A + B → products, doubling [A] alone doubles the rate, while doubling [B] alone has no effect … |
Chemistry
Rate law, order and molecularity |
Medium |
| 2054 |
For CHCl₃ + Cl₂ → CCl₄ + HCl, rate = k[CHCl₃][Cl₂]^½. What are the units of k? |
Chemistry
Rate law, order and molecularity |
Hard |
| 2055 |
The half-life of a first-order reaction is 10 minutes. What is its rate constant? |
Chemistry
Integrated rate equations |
Easy |
| 2056 |
For which order of reaction is the half-life independent of the initial concentration? |
Chemistry
Integrated rate equations |
Easy |
| 2057 |
How many half-lives are needed for 75% of a first-order reaction to be completed? |
Chemistry
Integrated rate equations |
Medium |
| 2058 |
A zero-order reaction has [R]₀ = 0.2 mol L⁻¹ and k = 0.01 mol L⁻¹ s⁻¹. What is its half-life? |
Chemistry
Integrated rate equations |
Medium |
| 2059 |
The acid-catalysed hydrolysis of ethyl acetate behaves as a first-order reaction even though it involves este… |
Chemistry
Integrated rate equations |
Hard |
| 2060 |
How does a catalyst increase the rate of a reaction? |
Chemistry
Temperature and rate |
Easy |
| 2061 |
In the Arrhenius equation k = A e^(−Ea/RT), what does the factor e^(−Ea/RT) represent? |
Chemistry
Temperature and rate |
Easy |
| 2062 |
A plot of ln k against 1/T for a reaction is a straight line. What is its slope? |
Chemistry
Temperature and rate |
Medium |
| 2063 |
According to collision theory, why do many collisions with enough energy still fail to give products? |
Chemistry
Temperature and rate |
Medium |
| 2064 |
The rate constant of a reaction doubles when the temperature rises from 300 K to 310 K. What is the approxima… |
Chemistry
Temperature and rate |
Hard |
| 2065 |
What is the ground-state outer electronic configuration of chromium (Z = 24)? |
Chemistry
Transition elements: general properties |
Easy |
| 2066 |
Why is zinc not regarded as a typical transition element? |
Chemistry
Transition elements: general properties |
Easy |
| 2067 |
Which 3d transition element shows the largest number of oxidation states? |
Chemistry
Transition elements: general properties |
Medium |
| 2068 |
Why does copper not liberate hydrogen gas from dilute hydrochloric acid? |
Chemistry
Transition elements: general properties |
Medium |
| 2069 |
Which ion would you expect to act as a strong reducing agent in aqueous solution? |
Chemistry
Transition elements: general properties |
Hard |
| 2070 |
Which ion is colourless in aqueous solution? |
Chemistry
Properties of transition metals |
Easy |
| 2071 |
Which catalyst is used in the contact process for making sulphuric acid? |
Chemistry
Properties of transition metals |
Easy |
| 2072 |
What is the spin-only magnetic moment of Mn²⁺ (Z of Mn = 25)? |
Chemistry
Properties of transition metals |
Medium |
| 2073 |
An ion of a 3d metal has a spin-only magnetic moment of 3.87 BM. How many unpaired electrons does it have? |
Chemistry
Properties of transition metals |
Medium |
| 2074 |
Which property is NOT typical of interstitial compounds of transition metals? |
Chemistry
Properties of transition metals |
Hard |
| 2075 |
What colour change is seen when acidified potassium dichromate acts as an oxidising agent? |
Chemistry
Oxides, oxoanions and important compounds |
Easy |
| 2076 |
Which ore is the starting material for the manufacture of potassium dichromate? |
Chemistry
Oxides, oxoanions and important compounds |
Easy |
| 2077 |
How many electrons are gained per permanganate ion when it acts as an oxidising agent in acidic solution? |
Chemistry
Oxides, oxoanions and important compounds |
Medium |
| 2078 |
What happens when an acid is added to a yellow solution of potassium chromate? |
Chemistry
Oxides, oxoanions and important compounds |
Medium |
| 2079 |
Why is hydrochloric acid not used to acidify KMnO₄ in redox titrations? |
Chemistry
Oxides, oxoanions and important compounds |
Hard |
| 2080 |
What is the most common oxidation state of the lanthanoids? |
Chemistry
Lanthanoids and actinoids |
Easy |
| 2081 |
What is the main cause of lanthanoid contraction? |
Chemistry
Lanthanoids and actinoids |
Easy |
| 2082 |
Why do zirconium and hafnium have almost identical atomic radii? |
Chemistry
Lanthanoids and actinoids |
Medium |
| 2083 |
Which lanthanoid ion is a good oxidising agent in aqueous solution? |
Chemistry
Lanthanoids and actinoids |
Medium |
| 2084 |
Why do actinoids show a wider range of oxidation states than lanthanoids? |
Chemistry
Lanthanoids and actinoids |
Hard |
| 2085 |
Which metal catalyst is used in the Haber process for ammonia? |
Chemistry
Applications of d- and f-block elements |
Easy |
| 2086 |
Which compound is widely used in photographic films because it is sensitive to light? |
Chemistry
Applications of d- and f-block elements |
Easy |
| 2087 |
Misch metal, used in lighter flints, mainly consists of: |
Chemistry
Applications of d- and f-block elements |
Medium |
| 2088 |
Which catalyst combination is used to polymerise ethene in the Ziegler process? |
Chemistry
Applications of d- and f-block elements |
Medium |
| 2089 |
A factory converts vegetable oils into solid fats by hydrogenation. Which catalyst is most likely used? |
Chemistry
Applications of d- and f-block elements |
Hard |
| 2090 |
What is the coordination number of the metal in [Co(en)₃]³⁺? |
Chemistry
Werner’s theory and key terms |
Easy |
| 2091 |
What is the oxidation state of iron in K₄[Fe(CN)₆]? |
Chemistry
Werner’s theory and key terms |
Easy |
| 2092 |
Which ligand is ambidentate? |
Chemistry
Werner’s theory and key terms |
Medium |
| 2093 |
One mole of CoCl₃·5NH₃ is treated with excess AgNO₃ solution. How many moles of AgCl are precipitated? |
Chemistry
Werner’s theory and key terms |
Medium |
| 2094 |
Which is a heteroleptic complex? |
Chemistry
Werner’s theory and key terms |
Hard |
| 2095 |
What is the IUPAC name of [Co(NH₃)₆]Cl₃? |
Chemistry
IUPAC nomenclature |
Easy |
| 2096 |
Which ending is used for the name of the metal when the complex is an anion? |
Chemistry
IUPAC nomenclature |
Easy |
| 2097 |
What is the IUPAC name of K₃[Fe(CN)₆]? |
Chemistry
IUPAC nomenclature |
Medium |
| 2098 |
What is the correct formula for tetraamminediaquacobalt(III) chloride? |
Chemistry
IUPAC nomenclature |
Medium |
| 2099 |
What is the IUPAC name of [CoCl₂(en)₂]Cl? |
Chemistry
IUPAC nomenclature |
Hard |
| 2100 |
Which type of isomerism is shown by [Co(NH₃)₅(NO₂)]Cl₂ and [Co(NH₃)₅(ONO)]Cl₂? |
Chemistry
Isomerism |
Easy |