Redox Reaction

What is the oxidation number of the chromium element in potassium dichromate (VI), K₂Cr₂O₇ ?

• +2

• +3

• +5

• +6

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

Iron (II) ions, Fe²⁺ in a solution can be changed to iron (III), Fe³⁺ by adding solution X. What is X?

• Sodium hydroxide

• Sodium thiosulphate

• Potassium hexacyanoferrate(II)

• Acidified potassium manganate (VII)

What is the meaning of reduction?

• Gain of electron

• Gain of oxygen

• Loss of hydrogen

• Increase in oxidation number

Which substance is an oxidising agent?

• Bromine water

• Magnesium powder

• Iron(II) chloride solution

• Potassium iodide solution

Tags

NGSS.HS-PS1-2

Which substance is used to change iron(III) ion to iron(II) ion?

• Bromine water

• Potassium iodide solution

• Potassium dichromate(VI) solution

• Acidified potassium manganate solution

What is the IUPAC name and oxidation number of copper element in the compound Cu₂O?

• Copper(I) oxide; +1

• Copper(I) oxide; +2

• Copper(II) oxide; +1

• Copper(II) oxide; +2

Which of the following occurs in oxidation reaction?

• loss of oxygen

• gain of hydrogen

• gain of electrons

• increase in oxidation number

Which equation represents a redox reaction?

• NaOH + HNO₃ → NaNO₃ +H₂O

• 2AgNO₃ + Zn → Zn(NO₃)₂ + 2Ag

• 2NaCl + Pb(NO₃)₂ → PbCl₂ + 2NaNO₃

• CaCO₃ + 2HCl → CaCl₂ + H₂O + CO₂

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

Which of the following is a reduction reaction?

• Carbon gains oxygen

• Zinc atom loses electrons

• Hydrogen sulphide loses hydrogen

• Bromine molecule gains electron

What is the oxidation number of X in XO₄^-?

• +4

• +5

• +7

• +8

Tags

NGSS.HS-PS1-2