In the reaction where copper(II) oxide reacts with hydrogen gas to form copper and water, which substance undergoes reduction?
Copper(II) oxide
The reaction is CuO + H2 → Cu + H2O. In terms of oxygen, reduction is the removal of oxygen from a substance (or addition of hydrogen), while oxidation is the addition of oxygen to a substance.
In this reaction, copper(II) oxide loses its oxygen and changes into copper metal. So copper(II) oxide is the substance that is reduced; in terms of electrons, Cu2+ gains two electrons to become Cu.
Hydrogen gains oxygen to form water, so hydrogen is oxidised and acts as the reducing agent. Water and copper are the products formed in the reaction; they are not the substances that undergo reduction.
Hence, Copper(II) oxide.
Which of the following is a balanced chemical equation for the reaction of sodium hydrogencarbonate with hydrochloric acid?
Which of the following reactions best represents a combination reaction?
Which of the following methods is commonly used to prevent rancidity in oils and fats?
Which of the following observations best confirms that carbon dioxide is produced when hydrochloric acid reacts with calcium carbonate?
What are the necessary conditions for corrosion or rusting of iron?
The balanced word equation for the reaction between magnesium carbonate and hydrochloric acid is:
What is the first step in balancing a chemical equation?
What is a common observation when magnesium reacts with air?
'Interconversion of states of matter' and 'burning' are examples of:
Formation of slaked lime is an example of:
Which of the following statement is/are true?
I. In physical change new substance is formed. substance is formed.
II. In chemical change no new substance is formed.
Which of the following cells involves similar chemical reactions?
The information not obtained from balanced chemical equation is
Oxygen cannot be obtained by which one of the following methods?
Which of the following statement is correct?
I. Insoluble salt is obtained by precipitation reaction.
II. Addition of oxygen or loss of hydrogen is called oxidation.