Advertisements
Advertisements
प्रश्न
Write the answer to the following.
Explain the similarity and difference in two events, namely adding NaOH to water and adding CaO to water.
Advertisements
उत्तर
- Chemical equations involved:
- \[\ce{NaOH(s)+H2O(l) -> {Na}^+_{(aq)} + OH^-_{(aq)} + \triangle (HEAT)}\]
- \[\ce{CaO(s) + H2O(l) -> Ca(OH)2(aq) + \triangle(HEAT)}\]
- Similarities:
- Both of the equations are exothermic. It means a lot of heat is evolved during the reaction.
- Both reactions form strong basic solutions
- Differences:
- Sodium Hydroxide is a strong base that dissociates to form Na+ and OH− ions While Calcium oxide adds water to form Calcium Hydroxide which further dissociates.
- NaOH is a monoacidic base. and CaO is a diacidic base.
- NaOH and CaO should be added to water gradually with constant stirring. CaO, on reacting with water, produces a basic solution called Calcium hydroxide which is used for whitewashing and this reaction is more dangerous as compared to NaOH.
APPEARS IN
संबंधित प्रश्न
Methyl orange is used as an indicator. It shows colour change in acid, base and neutral substance. Tabulate your result as follows:
| Indicator | Colour change | Inference |
| Methyl Orange | No change | ...................... |
| .................... | Acid | |
| Yellow | ....................... |
What is a balanced chemical equation? Why should a chemical equation be balanced?
Balance the chemical equation.
\[\ce{HNO3 +Ca(OH)2 -> Ca(NO3)2 + H2O}\]
Balance the following chemical equation.
\[\ce{NaOH + H2SO4 -> Na2SO4 + H2O}\]
Write the balanced chemical equation for the following reaction.
\[\ce{Barium chloride + Potassium sulphate → Barium sulphate + Potassium chloride}\]
What is a chemical equation? Explain with the help of an example.
Balance the following equation and add state symbols:
\[\ce{Zn + HCl -> ZnCl2 + H2}\]
Write the balanced equation for the following reaction, and add the state symbol:
Sodium hydroxide reacts with sulphuric acid to produce sodium sulphate and water.
With the help of an appropriate example, justify that some of the chemical reactions are determined by a change in colour.
Give a chemical equation for the reaction involved in the above case.
State one characteristic of the chemical reaction which takes place when lemon juice is added gradually to the potassium permanganate solution.
The chemical reaction between two substances is characterised by a change in colour from orange to green. These two substances are most likely to be ______.
A metal X forms a salt XSO4. The salt XSO4 forms a clear solution in water which reacts with sodium hydroxide solution to form a blue precipitate Y. Metal X is used in making electric wires and alloys like brass.
- What do you think metal X could be?
- Write the name, formula and colour of salt XSO4.
- What is the blue precipitate Y?
- Write a chemical equation of the reaction which takes place when salt XSO4 reacts with sodium hydroxide solution. Give the state symbols of all the reactants and products which occur in the above equation.
Write word equation for the following skeletal equation:
\[\ce{CO + O2 -> CO2}\]
Write word equation for the following skeletal equation:
\[\ce{Na + O2 -> Na2O}\]
Write word equation for the following skeletal equation:
\[\ce{AgBr -> Ag + Br2}\]
Balance the following chemical equation :
FeS + HCl → FeCl2 + H2S
Write your observation for the following chemical reaction and name the product formed :
When an aqueous solution of sodium chloride is mixed with an aqueous solution of silver nitrate.
Write symbolic representation for the following word equation and balance them :
Iron + Sulphur → Iron sulphide.
Balance the following equation .
N2 + O2 → NO
Balance the following equation. Also name the product formed.
CO2 + C → CO
Write the chemical equation for the following word equation and balance them.
Calcium oxide + Carbon dioxide → Calcium carbonate
What information does the following chemical equation convey?
Zn + H2SO4 → ZnSO4+ H2
What is the valency of :
carbon in CH4
Write the balanced chemical equation of the following reaction.
barium chloride + sulphuric acid → barium sulphate + hydrochloric acid
\[\ce{MnO2 + 4HCl -> MnCl2 + 2H2O + Cl2}\]
0.02 moles of pure MnO2 is heated strongly with conc. HCl. Calculate the mass of salt formed.
\[\ce{MnO2 + 4HCl -> MnCl2 + 2H2O + Cl2}\]
0.02 moles of pure MnO2 is heated strongly with conc. HCl. Calculate moles of chlorine gas formed.
When a potassium iodide solution is added to a solution of lead (II) nitrate in a test tube, a precipitate is formed.
Write the balanced chemical equation for this reaction.
In certain reaction a change of state is observed i.e. solid to liquid, liquid to gas etc. – State the change of state of the products – to give the respective reactant.
\[\ce{2H2O ->[electric][current] 2H2 + O2}\]
Representation of the results of a chemical change – is a chemical equation.
For the equation: FeCl3 + 3NH4OH 3NH4Cl + Fe(OH)3 ↓
Answer the following:
Name the reactants and the products in the above equation.
Give word equation for the following chemical reaction and give the names of the product formed.
\[\ce{CuO + H2SO4 -> CuSO4 + H2O}\]
Give word equation for the following chemical reaction and give the names of the product formed.
NH3 + HCl→ NH4Cl
Name the following:
The gas evolved when a dilute acid is added to chalk [limestone].
Give reason for the following:
Silver salts are kept in dark coloured bottles.
An element X is trivalent. Write the balanced equation for the combustion of X in oxygen.
Balance the following simple equation:
Fe + H2O ⇌ Fe3O4 + H2
Balance the following simple equation:
Fe2O3 + H2 → Fe + H2O
Underline the compound in the equation given below, it is incorrectly balanced and write the correct balancing for the same.
2H2O + 2Cl2 → 2HCl + O2
Underline the compound in the equation given below, it is incorrectly balanced and write the correct balancing for the same.
PbO2 +4HCl → PbCl2 + H2O + Cl2
What is called thermolysis reactions?
