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प्रश्न
Choose the correct alternative and rewrite the following sentence.
Which of the following is not required to find the pH of a given solution?
विकल्प
pH paper
Litmus paper
Standard pH value chart
- Universal indicator
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उत्तर
Litmus paper
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 | ....................... |
Translate the following statement into a chemical equation and then balance it.
Potassium metal reacts with water to give potassium hydroxide and hydrogen gas.
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.
Zinc oxide reacts with carbon, on heating, to form zinc metal and carbon monoxide. Write a balanced chemical equation for this reaction. Name
- oxidising agent, and
- reducing agent,
in this reaction.
Write your observations and name the product when
Iron nails are added to an aqueous solution of copper sulphate.
Write word equation for the following skeletal equation:
\[\ce{CO + O2 -> CO2}\]
Write word equation for the following skeletal equation:
\[\ce{NaOH + H2SO4 -> Na2SO4 + H2O}\]
Balance the following chemical equation :
Na2CO3 + HCl → NaCI + H2O + CO2
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 :
Pb3O4 → PbO + O2
Balance the following equation. Also name the product formed.
`"NaNO"_3 → "NaNO"_2 + "O"_2` Name of product (s)
Balance the following equation. Also name the product formed.
CO2 + C → CO
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
Raisins are wiped off gently before final weighing with the help of
Write the chemical equation for the following word equation and balance them.
Calcium oxide + Carbon dioxide → Calcium carbonate
Balance the following equation:
Fe + H2O → Fe3O4 + H2
Balance the following equation:
C + H2SO4 → CO2 + H2O + SO2
Balance the following equation:
KOH + Cl2 → KCl + KClO + H2O
Why should an equation be balanced? Explain with the help of a simple equation.
Choose the correct answer from the options given below.
The formula of sodium carbonate is Na2CO3 and that of calcium hydrogen carbonate is
Write the balanced chemical equation of the following reaction. potassium bicarbonate + sulphuric acid → potassium sulphate + carbon dioxide + water
Write the balanced chemical equations of the following reactions.
chlorine + sulphur dioxide + water → sulphuric acid + hydrogen chloride
Write the balanced chemical equation of the following reaction.
zinc sulphide + oxygen → zinc oxide + sulphur dioxide
Complete the following blank in the equation as indicated.
\[\ce{CaH2_{(s)} + 2H2O_{( aq)}-> Ca(OH)2_{(s)} + 2H2_{(g)}}\]
Moles: 1 mole + ______ `→` ______ + ______
(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?
What is thermit process?
Write word equation for the following molecular equation:
CuCo3 → CuO + CO2 [g]
Word equation:
State the characteristics or indications occurring 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 – lead [IV] 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.
2H2 + O2 → 2H2O
Give one example in the case where supplying energy [given below] is necessary for a chemical reaction.
Heat energy
Give word equation for the following chemical reaction and give the names of the product formed.
\[\ce{CuO + H2SO4 -> CuSO4 + H2O}\]
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.
Pb(NO3)2 + 2NH4OH → 2NH4N03 + Pb(OH)2↓
Write word equation for the following chemical reaction given below. Also state the observation seen in the case.
\[\ce{2SO2 + O2 ⇌[V2O5][450°C] 2SO3}\]
Give an example of a chemical equation in which two reactants form:
two product
Balance the following simple equation:
NaHCO3 + H2SO4 → Na2SO4 + H2O + CO2
Which of the following is the correct observation of the reaction shown in the above set up?
Dil. HCl is added to Zn granules. How will you prove that chemical change has taken place here? Support your response with two arguments.
Complete the following blank in the equation as indicated.
\[\ce{CaH2_{(s)} + 2H2O_{( aq)}-> Ca(OH)2_{(s)} + 2H2_{(g)}}\]
Molecules: 6.02 × 1023 + ______ `→` ______ + ______
