Assign oxidation states to atoms in compounds and ions using the standard rules, including hydrogen as -1 in metal hydrides and oxygen as -1 in peroxides, write them with the sign first (+2, -1) and explain why an uncombined element has oxidation state zero.
Tę umiejętność sprawdza 30 zadań wzorowanych na arkuszach IB z lat 2022–2026.
An ‘iodine clock’ experiment can be based on two reactions that occur at the same time. S2O82−(aq) + 2 I−(aq) → 2 SO42−(aq) + I2(aq) slow 2 S2O32−(aq) + I2(aq) → S4O62−(aq) + 2 I−(aq) fast The iodine formed in the slow reaction is removed at…
Propane undergoes complete combustion. C3H8(g) + 5 O2(g) → 3 CO2(g) + 4 H2O(l) (i) Calculate the standard enthalpy change of reaction, ΔH⊖, in kJ mol−1, for the combustion of propane. Use section 13 of the data booklet. (ii)…
What happens to hydrogen in the following reaction? Each option states whether hydrogen is oxidized or reduced and the change in its oxidation state. Mg(s) + 2 HCl(aq) → MgCl2(aq) + H2(g) A. Oxidized, from +1 to 0 B. Oxidized, from 0 to +1 C. Reduced,…
What is the oxidation state of chlorine in Cl2O7? A. −7 B. +3.5 C. +7 D. +14
In which species does an atom have the oxidation state +5? I. IF5 II. H3PO4 III. N2O4 A. I and II only B. I and III only C. II and III only D. I, II and III
Sulfur has different oxidation states in hydrogen sulfide, H2S, and in sulfurous acid, H2SO3. Which pair of values is correct? A. H2S: +2; H2SO3: +4 B. H2S: −2; H2SO3: +6 C. H2S: −2; H2SO3: +4 D.…
In which compound does nitrogen have an oxidation state of +3? A. NH3 B. HNO2 C. NO2 D. HNO3
In the Claus process, used to recover sulfur from refinery gases, sulfur dioxide reacts with hydrogen sulfide, H2S, to form sulfur. (i) State the oxidation state of sulfur in SO2 and in the sulfur produced. (ii) Deduce the balanced equation for…
Methanoic acid, HCOOH, is a weak acid, and solutions of it are often used as acidic buffers. A chemist prepared a 0.500 mol dm−3 solution of methanoic acid, in which two conjugate acid–base pairs are present. (i) For each pair, state the…
What are the oxidation states of the elements in K2MnO4? A. K: +1, Mn: +6, O: −2 B. K: +1, Mn: +7, O: −2 C. K: +2, Mn: +4, O: −2 D. K: +1, Mn: +6, O: −1
Which row identifies the oxidizing agent and the reducing agent in the reaction below? 3 Cu(s) + 2 NO3−(aq) + 8 H+(aq) → 3 Cu2+(aq) + 2 NO(g) + 4 H2O(l) A. Oxidizing agent: Cu, reducing agent: NO3− B. Oxidizing agent: NO3−, reducing…
Which statements are correct for the complex ion [CoCl4]2−? I. The oxidation state of cobalt is +4. II. The chloride ions act as Lewis bases. III. The coordination number of cobalt is 4. A. I and II only B. I and III only C. II and III only D. I, II…
What is the oxidation state of chromium in the complex [Cr(NH3)4Cl2]Cl? A. +1 B. +2 C. +3 D. +7
Deduce the oxidation state of chlorine in each of the three chlorine-containing species in the equation. Cl2: HOCl: Cl−:
Chloride ions can act as ligands towards transition metal ions. Three compounds of chromium that differ in the number of chloride ions bonded directly to the chromium ion have the formulas and colours shown. (i) Deduce the charge of the complex ion in…
Which element forms a stable compound in which its oxidation state is +6? A. Ti B. V C. Cr D. Zn
The overall reaction during the discharge of a lead–acid battery is: Pb(s) + PbO2(s) + 2 H2SO4(aq) → 2 PbSO4(s) + 2 H2O(l) Which statement is correct? A. The oxidation state of lead in Pb(s) changes from +2 to 0. B. The oxidation state of sulfur…
(i) State the oxidation states of carbon in carbon monoxide and in carbonyl chloride. (ii) For each of CO and Cl2 in the forward reaction, state whether it acts as an oxidizing agent or a reducing agent, and whether it is oxidized or reduced.
What is the oxidation state of platinum in the complex ion [PtCl5(NH3)]−? A. +1 B. +2 C. +3 D. +4
In which species is the oxidation state of cobalt different? A. [CoCl4]2− B. [Co(H2O)6]2+ C. [Co(NH3)6]2+ D. [Co(NH3)4Cl2]+
In which pair of species does nitrogen have the same oxidation state? A. HNO2 and N2O3 B. NO3− and N2O4 C. NH4+ and N2H4 D. NO and N2O
In which reaction does N2 act as a reducing agent? A. N2(g) + 3 H2(g) → 2 NH3(g) B. 3 Mg(s) + N2(g) → Mg3N2(s) C. N2(g) + O2(g) → 2 NO(g) D. 6 Li(s) + N2(g) → 2 Li3N(s)
(i) Identify the oxidation state of metal S in SSO4. (ii) Deduce the order of reactivity of the five metals, from the most reactive to the least reactive.
State the oxidation state of manganese in the permanganate ion, MnO4−.
Which change involves the oxidation of chlorine? A. Cl2 → Cl− B. ClO4− → ClO3− C. Cl2 → ClO3− D. HCl → Cl−
Determine the oxidation state of iodine in the iodate ion, IO3−.
Determine the oxidation state of carbon in methanol, CH3OH.
The presence of calcium nitride in the product can be demonstrated by adding water. The nitride is hydrolysed to form calcium hydroxide and ammonia. (i) Calculate coefficients that balance the equation for the reaction: __ Ca3N2(s) + __ H2O(l) →…
Calculate the oxidation state of sulfur in cobalt(II) disulfide, CoS2.
In which species would nitrogen be oxidized if it were converted to N2O? A. NO2 B. NH4+ C. HNO3 D. N2O3
Zapisujemy na Twoim urządzeniu to, bez czego serwis nie działa, np. zalogowanie. Plików analitycznych użyjemy tylko za Twoją zgodą. Szczegóły w polityce prywatności.