Tag: the d-and f-block elements

Questions Related to the d-and f-block elements

Mass (g)
Empty crucible $22.01$
Crucible and copper oxide $42.01$
Crucible and copper product $(1^{st}mass)$ $39.87$
Crucible and copper product $(2^{nd}mass)$ $38.01$
Crucible and copper product $(3^{rd}mass)$ $38.01$

Copper ions can have multiple oxidative states. The data table above was obtained during a lab in which an unknown copper oxide was heated in a crucible.
From this data, what is the name of the unknown copper oxide?

chemistry d- and f-block elements some important compounds of transition elements general properties of transition metals the d-and f-block elements

  1. Copper(I) oxide.

  2. Copper (II) oxide.

  3. Copper (I) peroxide.

  4. Copper (II) peroxide.

Show answer
Correct Option: A
State True or False.
Fe$ _3$O$ _4$ is mixed oxide of FeO and Fe$ _2$O$ _3$. 
chemistry d- and f-block elements some important compounds of transition elements general properties of transition metals the d-and f-block elements

  1. True

  2. False

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Correct Option: A
Explanation:

Iron (II,III) oxide is the chemical compound with formula $Fe _3O _4$. It occurs in nature as the mineral magnetite. It is one of a number of iron oxides, the others being iron(II) oxide ($FeO$), which is rare, and iron(III) oxide ($Fe _2O _3$) also known as hematite. $Fe _3O _4$ contains both $Fe^{2+}$ and $Fe^{3+}$ ions and is sometimes formulated as FeO ∙ Fe2O3. 

The molecular formula of Rinmann's green is:

chemistry d- and f-block elements some important compounds of transition elements general properties of transition metals the d-and f-block elements

  1. $FeSO _{4}7H _{2}O$

  2. $CrCl _{3}$

  3. $NiSO _{4}7H _{2}O$

  4. $CoOZnO$

Show answer
Correct Option: D
Explanation:

Rinmanns green (CoO.ZnO) Cobalt green, is a translucent green pigment made by mixing cobalt(II) oxide and zinc oxide.