Chemical Reacti...

A chemical change involves the formation of a new substance, with properties different from those of the reactants. Which among the following is not a chemical change?

Magnesium burns in air with a dazzling white flame and the reaction may be represented as:



The reaction may be classified as a/an

Which is the reducing agent in the thermite reaction carried out for repairing of the railway tracks?

Neutralisation reaction is an example of

Directions: Analyse the given chemical change and select the correct option in relation to this reaction.

What happens when the potassium iodide solution is added to a solution of lead nitrate?

Analyse the chemical reagents and the suggested containers for storing them.

Which of the following combinations are not recommended?

A. AgNO₃ in copper vessel
B. CuSO₄ in silver vessel
C. Cu(NO₃)₂ in an iron container
D. H₂SO₄ in Al vessel

Analyse the two statements given below and select the correct option.

Statement I: Melting of ice is an endothermic process.
Statement II: Freezing of water is exothermic.

Sulphur burns in air to form its oxide and the reaction can be represented by the following equation:



Which of the following statements in relation to this reaction is incorrect?

Which of the following processes results in a chemical change?

The chemical reactions and its corresponding observable features are listed below.

Consider the following hypothetical reaction and fill in the blanks by choosing the correct option.

x + y - z x - z + y

In the given chemical reaction, old bonds between _________ are broken and new bonds between _________ are formed.

What is the visual indication that a chemical change has occurred when an aqueous solution of sodium sulphate is mixed with that of barium chloride?

Quicklime combines with water to form 'X'. Identify 'X' and indicate the energy change involved.

A solution of calcium hydroxide is used for whitewashing the walls. After two to three days of whitewashing, the walls start shining due to the formation of the compound:

Which of the following reactions requires the highest temperature to occur?

Consider the following reaction:

Al(s) + Fe₂O₃(s) Al₂O₃(s) + Fe(s)

Which of the following statements is not correct about the given reaction?

When the reaction Pb(NO₃)₂ PbO + NO₂ + O₂ is balanced, the coefficients of the reactants and products in the balanced reaction will respectively be:

Consider the following chemical reaction:

HNO₃(aq) + KOH(aq) KNO₃(aq) + H₂O(l)

The given reaction is an example of

Consider the following statements about redox reactions:

(i) A substance is said to be reduced if it gains electrons during a reaction.
(ii) A substance is said to be oxidised if it gains hydrogen during a reaction
(iii) A substance is said to be reduced if it loses oxygen during a reaction.
(iv) A substance is said to be reduced if it gains hydrogen during a reaction.

Which of the given statements is/are correct?