Class 10th science ch1

Sodium and chlorine are reacted, and as a result, sodium chloride is formed, which is also called table salt. What option gives the reactants and products of the reaction?

• Reactants – sodium; products – chlorine

• Reactants – sodium and table salt; products – chlorine

• Reactants – tables salt; products – sodium and chlorine

• Reactants – sodium and chlorine; products – sodium chloride

Which of the following reaction can also be termed a thermal decomposition reaction?

• Combination reaction

• Decomposition reaction

• Displacement reaction

• Double displacement reaction

The image shows some chemical reactions.

Which option identifies the reactants and products of the reactions?

• Reactants H, Cl and HCl

  Products 2H, O, and H,0

• Reactants HCl and 2H,0

  Products H, CI, 2H and 0,

• Reactants H, C1, 2H and 0,

  Products HCl and 2H,0

• Reactants 2H, 0, and H,0

  Products H, Cl and HCl

A student performs an experiment to form aluminium chloride from aluminium and chlorine. Which of the following option gives the chemical equation of the reaction?

• Al + Cl₂ → AlCl₂

• 2Al + Cl₂ → 2AlCl

• 2Al + 3Cl₂ → 2AlCl₃

• 3Al + 3Cl₂ → 3AlCl₃

Give the ratio in which hydrogen and oxygen are present in water by volume.

• 1:2

• 2:1

• 1:1

• 1:8

A researcher adds barium hydroxide to hydrochloric acid to form a white-coloured barium chloride. Which of the following option gives the balanced chemical equation of the reaction?

• HCl + Ba(OH)₂ → BaCl₂ + 2HOH

  
  

• 2HCl + Ba(OH)₂ → BaCl₂ + 2HOH

• 2HCl + Ba(OH)₂ → BaH₂ + 2HCl + O₂

• HCl + 2Ba(OH) → 2BaCl₂ + 2HOH + O₂

One of the following processes does not involve a chemical reaction, that is:

• Melting of candle wax when heated

• Burning of candle wax when heated

• Digestion of food in your stomach

• Ripening of banana

A student wrote a chemical equation of the reaction between carbon monoxide and hydrogen as,

CO2 + 2H₂ → CH₃OH.

How can the reaction be classified?

• The reaction is an example of a combination reaction as a compound separates into two compounds.

  
  

• The reaction is an example of a decomposition reaction as a compound dissociates into two compounds.

  
  

• The reaction is an example of a combination reaction as two compounds react to form a single compound.

• The reaction is an example of a decomposition reaction as two compounds react to form a single compound.

The chemical formula of magnesium oxide is ______.

• MgO₂

• Mg₂O

• MgO

• Mg(OH)₂

Which of the following reactions is used in black-and-white photography?

• Combination Reaction

• Decomposition Reaction

• Displacement reaction

• Oxidation reaction