Advertisements
Advertisements
प्रश्न
Write scientific reason.
Adding zinc particles to a solution of copper sulphate makes the blue solution colorless.
उत्तर
- Zinc is more reactive than copper.
- Therefore, zinc displaces copper from copper sulphate solution.
\[\ce{\underset{\text{sulphate}}{\underset{\text{Copper}}{CuSO_{4(aq)}}} + \underset{\text{Zinc}}{Zn_{(s)}} -> \underset{\text{sulphate}}{\underset{\text{Zinc}}{ZnSO_{4(aq)}}} + \underset{\text{Copper}}{Cu_{(s)}}}\] - The blue colour of copper sulphate solution fades due to the formation of colourless zinc sulphate.
Hence, adding zinc particles to a solution of copper sulphate makes the blue solution colorless.
APPEARS IN
संबंधित प्रश्न
Balance the chemical equation.
\[\ce{HNO3 +Ca(OH)2 -> Ca(NO3)2 + H2O}\]
Write the balanced chemical equation for the following reaction.
\[\ce{Calcium hydroxide + Carbon dioxide → Calcium carbonate + Water}\]
Correct and balance the following equation:
N + H 
NH3
Write complete balanced equation for the following reaction:
Calcium (solid) + water (liquid) 
Calcium Hydroxide (solution) + Hydrogen (gas)
Balance the given equation:
NH3 + CuO 
Cu +N2 +H2O
Write balanced chemical equation from the following information:
An aqueous calcium hydroxide solution (lime water) reacts with carbon dioxide gas to produce a solid calcium carbonate precipitate and water.
Convey the following information in the form of a balanced chemical equation:
"An aqueous solution of ferrous sulphate reacts with an aqueous solution of sodium hydroxide to form a precipitate of ferrous hydroxide and sodium sulphate remains in solution."
Write balanced chemical equation with state symbols for the following reaction:
Sodium hydroxide solution reacts with hydrochloric acid solution to produce sodium chloride solution and water.
Ammonia reacts with oxygen to form nitrogen and water. Write a balanced chemical equation for this reaction. Add the state symbols for all the reactants and products.
When potassium nitrate is heated, it decomposes into potassium nitrite and oxygen. Write a balanced equation for this reaction and add the state symbols of the reactants and products.
What is meant by chemical reaction? Explain with the help of an example.
One of the following does not happen during a chemical reaction. This is:
(a) Breaking of old chemical bonds and formation of new chemical bonds
(b) Formation of new substances with entirely different properties
(c) Atoms of one element change into those of another element to form new products.
(d) A rearrangement of atoms takes place to form new products.
Which of the following does not involve a chemical reaction?
When metal X is treated with a dilute acid Y, then a gas Z is evolved which burns readily by making a little explosion.
(a) Name any two metals which can behave like metal X.
(b) Name any two acids which can behave like acid Y.
(c) Name the gas Z.
(d) Is the gas Z lighter than or heavier than air?
(e) Is the reaction between metal X and dilute acid Y, exothermic or endothermic?
(f) By taking a specific example of metal X and dilute acid Y, write a balanced chemical equation for the reaction which takes place. Also indicate physical states of all the reactants and products.
The metal M reacts vigorously with water to form a solution S and a gas G. The solution S turns red litmus to blue whereas gas G, which is lighter than air, burns with a pop sound. Metal M has a low melting point and it is used as a coolant in nuclear reactors.
(a) What is metal M?
(b) What is solution S? Is it acidic or alkaline?
(c) What is gas G?
(d) Write a balanced chemical equation for the reaction which takes place when metal M reacts with water.
(e) Is this reaction exothermic or endothermic?
Write the balanced equation for the following chemical reaction.
\[\ce{Barium chloride + Aluminium sulphate -> Barium sulphate + Aluminium chloride}\]
Write word equation for the following skeletal equation:
\[\ce{Ca + O2 → CaO}\]
Balance the following equation. Also name the product formed.
`"Zn" + "HCI" → "ZnCI" _2 + "H"_2`
While performing the experiment with raisins to determine the percentage of water absorbed by them, a student made following measurements:
Mass of water in the beaker = 40 g
Mass of raisins before soaking = 5 g
Mass of raisins after soaking for 2 hours = 8 g
Mass of water left in the beaker after the experiment = 35 g
The percentage of water absorbed by raisins is:
In the experiment for determining the percentage of water absorbed by raisins, we do the final weighing of the raisins after keeping them dipped in water for about one hour. For the accuracy of the result, the extra water from the surface of the soaked raisins is removed by
What is a chemical equation? Why it is necessary to balance it?
\[\ce{MnO2 + 4HCl -> MnCl2 + 2H2O + Cl2}\]
0.02 moles of pure MnO2 is heated strongly with conc. HCl. Calculate mass of MnO2 used.
\[\ce{MnO2 + 4HCl -> MnCl2 + 2H2O + Cl2}\]
0.02 moles of pure MnO2 is heated strongly with conc. HCl. Calculate moles of salt formed.
Choose the correct alternative and rewrite the following sentence.
Which of the following is not required to find the pH of a given solution?
Write word equation for the following molecular equation:
\[\ce{N2 + 3H2 ⇌[Fe - 450°C][200 atoms] 2NH3 + \triangle}\]
Word equation:
State why [+ Δ] indication is seen after NH3.
State what 200 atmospheres – indicates.
State the function of Fe in the above reaction.
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 – mercury [II] oxide.
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.
\[\ce{C +2S -> CS2}\]
Representation of the results of a chemical change – is a chemical equation.
For the equation: FeCl3 + 3NH4OH 3NH4Cl + Fe(OH)3 ↓
Answer the following:
Write the word equation for the above molecular equation.
Give an example of a chemical equation in which two reactants form:
two product
\[\ce{2KClO3->[MnO2] 2KCl + 3O2[g] - is a balanced equation.}\]
State what is a ‘balanced equation’.
Balance the following simple equation:
Al + N2 → AlN
Balance the following simple equation:
K + CO2 → K2O + C
Balance the following simple equation:
K + H2O → KOH + H2
Balance the following simple equation:
Zn + NaOH → Na2ZnO2 + H2
CaCO3 + 2HCl[dil.] → CaCl2 + H2O + CO2 [g]
State the information not conveyed by the above chemical equation.
Write a balanced equation for the following word equation:
Lead dioxide [lead (IV) oxide] → Lead monoxide + Oxygen
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 names of reactants and products of chemical reaction.
The following reaction is an example of a `4"NH"_3("g") + "SO"_2 -> 4"NO"("g") + 6"H"_2"O"("g")`
- displacement reaction
- combination reaction
- redox reaction
- neutralisation reaction
When aqueous solutions of potassium iodide and lead nitrate are mixed an insoluble substance separates out. The chemical equation for the reaction involved is:
