Advertisements
Advertisements
Question
Write the answer to the following.
Explain the similarity in two events, namely adding NaOH to water and adding CaO to water.
Advertisements
Solution
When NaOH and CaO are dissolved independently in water, solid NaOH dissolves and releases heat, raising the temperature. This is an exothermic process. A significant amount of heat is released when solid CaO dissolves in water to create Ca(OH)2. Additionally, this process is exothermic. Both reactions result in a single product and are combination reactions.
\[\ce{NaOH_{(s)} + H2O -> NaOH_{(aq)} + Heat}\]
\[\ce{CaO_{(s)} + H2O -> Ca(OH)_{2(aq)} + Heat}\]
APPEARS IN
RELATED QUESTIONS
Write the balanced chemical equation for the following reaction.
\[\ce{Aluminium + Copper chloride -> Aluminium chloride + Copper}\]
Translate the following statement into a chemical equation and then balance the equation:
Phosphorus burns in oxygen to give phosphorus pentoxide.
Aluminium burns in chlorine to form aluminium chloride (AlCl3). Write a balanced chemical equation for this reaction.
Write the balanced equation for the following reaction, and add the state symbol:
Magnesium carbonate reacts with hydrochloric acid to produce magnesium chloride, carbon dioxide and water.
With the help of an appropriate example, justify that some of the chemical reactions are determined by a change in temperature.
Give a chemical equation for the reaction involved in the above case.
Which of the following are endothermic reactions and which are exothermic reactions?
- Burning of natural gas
- Photosynthesis
- Electrolysis of water
- Respiration
- Decomposition of calcium carbonate
When a mixture of gases X and Y is compressed to 300 atm pressure and then passed over a catalyst consisting of a mixture of zinc oxide and chromium oxide (heated to a temperature of 300°C), then an organic compound Z having the molecular formula CH4O is formed. X is a highly poisonous gas which is formed in appreciable amounts when a fuel burns in a limited supply of air; Y is a gas which can be made by the action of a dilute acid on an active metal; and Z is a liquid organic compound which can react with sodium metal to produce hydrogen gas.
- What are X, Y and Z?
- Write a balanced chemical equation of the reaction which takes place when X and Y combine to form Z. Indicate the conditions under which the reaction occurs.
Name the various types of chemical reactions.
What happens when silver nitrate solution is added to sodium chloride solution?
- Write the equation for the reaction which takes place.
- Name the type of reaction involved.
The removal of oxygen from a substance is called ______.
Name the type of chemical reaction shown by the following equation:
2Mg+ O2 → 2MgO
Why do we need to balance chemical equations?
Complete the following equation:
CH2 + H5OH `("Hot Conc." H_2SO_4)/`>
The step(s) necessary for determining the percentage of water absorbed by raisins is/are:
Explain the terms with examples.
Balanced equation
State the information conveyed by the following equation:
Zn(s) + 2HCl(aq) → ZnCl2(aq) + H2 ↑
Write the chemical equation for the following word equation and balance them.
Nitrogen + Oxygen → Nitrogen monoxide
Balance the following equation:
Fe + H2O → Fe3O4 + H2
Balance the following equation:
NaHCO3 → Na2CO3 + H2O + CO2
Write the balanced chemical equation of the following reaction. sodium hydroxide + sulphuric acid → sodium sulphate + water
Write the balanced chemical equation of the following reaction.
ammonia + oxygen → nitric oxide + water
(a) Give only one suitable chemical test to identify the following gases.
- Ammonia
- Sulphur dioxide
- Hydrogen Chloride
- Chlorine
- Carbon Dioxide
- Oxygen
- Hydrogen
(b) Select a basic gas mentioned in Q.1 (a). How is the basic nature suspected?
(c)Select acidic gases from the gases mentioned in Q.1 (a). How is the acidic nature suspected?
(d) State the gas responsible for bleaching action.
(e)Which gas turn blue cobalt chloride paper light pink?
Answer the following question:
How do acids and bases react with each other? What is the name of the process? What product is obtained from these reactions?
A chemical reaction is generally accompanied by certain external indications or characteristics. These include – change of – (a) colour (b) state (c) smell (d) evolution of gas (e) formation of precipitate (f) evolution or absorption of heat. With reference to change of colour – state the change in colour seen when the following are heated – zinc carbonate.
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.
NH3 + HCl ⇌ NH4Cl
Representation of the results of a chemical change – is a chemical equation.
For the equation: FeCl3 + 3NH4OH 3NH4Cl + Fe(OH)3 ↓
Answer the following:
Is the equation given above a balanced equation. Give reasons.
Representation of the results of a chemical change – is a chemical equation.
For the equation: FeCl3 + 3NH4OH 3NH4Cl + Fe(OH)3 ↓
Answer the following:
What is the indications of the arrow between the reactants and the products and of the arrow pointing downwards at the end.
Give word equation for the following chemical reaction and give the names of the product formed.
Zn + 2HC1→ ZnCl2 + H2
Name the following:
The gas evolved when a dilute acid is added to chalk [limestone].
Write word equation for the following chemical reaction given below. Also state the observation seen in the case.
\[\ce{Na2SO3 + 2HCl ->[\triangle] 2NaCl + H2O + SO2}\]
Write word equation for the following chemical reaction given below. Also state the observation seen in the case.
\[\ce{2SO2 + O2 ⇌[V2O5][450°C] 2SO3}\]
Balance the following simple equation:
Fe + Cl2 → FeCl3
Balance the following simple equation:
Al + H2O → Al2O3 + H2
Balance the following simple equation:
Fe2O3 + CO → Fe + CO2
With reference to a chemical equation state which of the statements 1 to 5 pertain to A or B.
A: Information provided by a chemical equation.
B: Limitations of a chemical equation.
- The nature of the individual elements.
- The speed of the reaction.
- The state of matter in which the substance is present.
- The completion of the reaction.
- The direction of the reaction.
Underline the compound in the equation given below, it is incorrectly balanced and write the correct balancing for the same.
Cl2 + 2H2O + SO2 → 4HCl + H2SO4
Underline the compound in the equation given below, it is incorrectly balanced and write the correct balancing for the same.
6NaOH + 3Cl2 → 6NaCl + NaClO3 + 3H2O
Write three steps of writing chemical equations with example?
Balance the given chemical reaction as per the instructions below.
\[\ce{NaOH + H2SO4 -> Na2SO4 + H2O}\]
Write the number of atoms of reactants and products.
Why should a magnesium ribbon be cleaned before burning in air?
