Remedial - PT, Redox, Speed, ABS

Which statement is correct when a mixture of ammonium carbonate and aqueous potassium hydroxide is warmed?

• A gas is produced which forms white precipitate in limewater.

• A gas is produced which turns damp blue litmus paper red.

• A gas is produced which turns damp red litmus paper blue.

• A gas is produced which extinguishes a lighted splint with a “pop” sound.

In which equation(s) does the oxidation state of manganese decrease?

(1)  MnO₂   +    4HCl  →   MnCl₂   +  Cl₂   +   2H₂O

(2)  MnO₄^- +  8H⁺  +  5Fe²⁺  →  5Fe³⁺  +  Mn²⁺  + 4H₂O

(3)  2Mn(OH)₂ +  H₂O₂  →   Mn₂O₃  +  3H₂O

• 1, 2 and 3

• 1 and 2 only

• 2 and 3 only

• 3 only

Using your knowledge of the halogens and their compounds, which statement(s) is/are correct?

(1) Silver astatide is an ionic compound.

(2) Bromine displaces astatine from a solution of potassium astatide.

(3) Astatine is a gas at room temperature.

• 1 and 2

• 1 and 3

• 2 only

• 3 only

Which property of aluminium suggests it is not a transition metal?

• conducts electricity

• high melting point

• low density

• malleable

Which diagram shows the graphs of reaction 1 & 2 (volume of hydrogen produced, V, against time, t) ?

 

Reaction 1:

10 g of magnesium ribbon with excess 2.0 mol/dm³ hydrochloric acid

Reaction 2:

 5 g of magnesium powder with excess 2.0 mol/dm³ hydrochloric acid

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