Advertisements
Advertisements
प्रश्न
Solid calcium oxide reacts vigorously with water to form calcium hydroxide accompanied by liberation of heat. This process is called slaking of lime. Calcium hydroxide dissolves in water to form a solution called lime water. Which among the following is (are) true about slaking of lime and the solution formed?
- It is an endothermic reaction
- It is an exothermic reaction
- The pH of the resulting solution will be more than seven
- The pH of the resulting solution will be less than seven
विकल्प
(i) and (ii)
(ii) and (iii)
(i) and (iv)
(iii) and (iv).
Advertisements
उत्तर
(ii) and (iii)
Explanation -
Slaking of lime is an exothermic process. Lime (CaO) dissolves in water to form calcium hydroxide called slaked lime Ca(OH)2. Since it is a base, the pH of solution will become more than seven (7).
APPEARS IN
संबंधित प्रश्न
Why it is necessary to balance a chemical equation ?
Balance the following equation:
N2 + H2 → NH3
Write balanced chemical equations for the following word equation:
Calcium oxide + water → Calcium hydroxide
Balance the following equation:
`N_2+O_2 → NO`
State the information provided by a chemical equation.
Balance the following equation:
\[\ce{ZnS + O2->ZnO + SO2}\]
Underline the incorrectly balanced compound equation and rewrite the correct equation.
\[\ce{2Na + 3H2O->2NaOH + H2}\]
Balance the following important equation:
ZnO + NaOH → Na2ZnO2 + H2O
Balance the following important equation:
NaAlO2 + H2O → NaOH + Al(OH)3
Balance the following important equation:
Pb(NO3)2 + HCl → PbCl2 + HNO3
Balance the following important equation:
\[\ce{NH4Cl + Ca(OH)2 → CaCl2 + H2O + NH3}\]
Balance the following important equation:
NH3 + O2 → NO + H2O (catalytic oxidation of NH3)
Before burning in air, the magnesium ribbon is cleaned by rubbing with sand paper to:
Magnesium ribbon is rubbed before burning because it has a coating of ____________.
Barium chloride on reacting with ammonium sulphate forms barium sulphate and ammonium chloride. Which of the following correctly represents the type of the reaction involved?
- Displacement reaction
- Precipitation reaction
- Combination reaction
- Double displacement reaction
Write the balanced chemical equations for the following reactions and identify the type of reaction in each case.
- Iron (III) oxide reacts with aluminum and gives molten iron and aluminum oxide.
- Magnesium ribbon is burnt in an atmosphere of nitrogen gas to form solid magnesium nitride.
- Chlorine gas is passed in an aqueous potassium iodide solution to form potassium chloride solution and solid iodine.
- Ethanol is burnt in air to form carbon dioxide, water and releases heat.
Write a balanced chemical equation of the following reaction and also classify them.
Iron (III) oxide on heating with carbon monoxide gas reacts to form solid iron and liberates carbon dioxide gas.
What are the points to be followed while balancing a chemical equation?
Write the balanced equation for the following chemical reaction.
\[\ce{Sodium + Water -> Sodium hydroxide + Hydrogen}\]
