Advertisements
Advertisements
प्रश्न
During the reaction of some metals with dilute hydrochloric acid, following observations are made.
The temperature of the reaction mixture rises when aluminium (Al) is added.
Explain this observation giving suitable reason.
Advertisements
उत्तर
The reaction of aluminium (Al) with dilute HCl is of exothermic nature. Therefore the temperature rises.
APPEARS IN
संबंधित प्रश्न
Corrosion can be prevented by using ……………. solution.
What are anti-oxidants?
When SO2 gas is passed through saturated solution of H2S, the following reaction occurs:
SO2 + 2H2S → 2H2O + 3S
In this reaction, which substance is oxidised and which one is reduced?
The addition of oxygen to a substance is called ______ whereas removal of oxygen is called ______.
Identify the substances that are oxidised and the substances that are reduced in the following reaction.
\[\ce{CuO_{(s)} + H2_{(g)} -> Cu_{(s)} + H2O_{(l)}}\]
State whether the following conversion is oxidation or reduction:
PbO2 + SO2→ PbSO4
State whether the following conversion is oxidation or reduction:
Cu2+ + 2 e-→ Cu
Reacting with water, an active metal produces
Which of the following statements about hydrogen is incorrect?
Complete and balance the following equation:
Zn +_________________→ZnCl2 + H2
When the positive charge on an ion increases or the negative charge on them decreases it is called as _______.
Identify the following reactions as oxidation or reduction
- Na → Na+ + e
- Fe3+ + 2 e- → Fe+
\[\ce{MnO2 + 4HCl -> + 2H2O + Cl2}\]
Identify the substance oxidized in the above equation.
Identify the oxidising agent (oxidant) in the following reactions.
`"CuO" + "H"_2 -> "Cu" + "H"_2"O"`
A silver article generally turns black when kept in the open for a few days. The article when rubbed with toothpaste again starts shining.
- Why do silver articles turn black when kept in the open for a few days? Name the phenomenon involved.
- Name the black substance formed and give its chemical formula.
The tarnishing of metals is an example of ______ reaction.
Identify the following reactions as oxidation/reduction/redox reaction
Zn + CuSO4 → Cu + ZnSO4
Identify the following reactions as oxidation/reduction/redox reaction
CuO+H2 → Cu+H2O
Find the oxidation number of the element in the following compound.
Zn in ZnSO4
