'Interconversion of states of matter' and 'burning' are examples of:
physical and chemical change, respectively
Interconversion of states (melting, boiling, condensation, freezing) changes only the physical state; no new substance forms and the change is reversible — a physical change.
Burning (combustion) forms new substances such as CO2, water and ash with release of heat and light, and cannot be reversed — a chemical change.
Hence, they are physical and chemical change, respectively.
Which of the following is a balanced chemical equation for the reaction of sodium hydrogencarbonate with hydrochloric acid?
In the reaction where copper(II) oxide reacts with hydrogen gas to form copper and water, which substance undergoes reduction?
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?
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.