Advertisements
Advertisements
Question
Write any two observations in an activity which may suggest that a chemical reaction has taken place. Give an example in support of your answer.
Advertisements
Solution
Two observations that may suggest that a chemical reaction has taken place are
(i) evolution of a gas and
(ii) change in temperature.
For example, zinc granules react with dilute sulphuric acid to evolve hydrogen gas, which is easily observed by the bubbles of hydrogen gas appearing around zinc granules. Also, the flask becomes hot, which shows heat is evolved during the reaction—that is, change in temperature.
Zn + H2SO4 → ZnSO4 + H2↑ + Heat
RELATED QUESTIONS
Translate the following statement into chemical equation and then balance it.
Hydrogen gas combines with nitrogen to form ammonia
Carbon monoxide reacts with hydrogen under certain conditions to form methanol (CH3OH). Write a balanced chemical equation for this reaction indicating the physical states of reactants and product as well as the conditions under which this reaction takes place.
Rewrite the following information in the form of a balanced chemical equation:
Magnesium burns in carbon dioxide to form magnesium oxide and carbon.
Substitute formulae for names and balance the following equation:
Calcium carbonate reacts with hydrochloric acid to produce calcium chloride, water and carbon dioxide gas.
Write word equation for the following skeletal equation:
\[\ce{KClO3 -> KCl + O2}\]
Write symbolic representation for the following word equation and balance them :
Calcium carbonate → Calcium oxide + Carbon dioxide.
Balance the following equation :
Pb3O4 → PbO + O2
Balance the following equation. Also name the product formed.
`"KCIO"_3 → "KCI" +"O"_2`
Balance the following equation. Also name the product formed.
`"Na"+ "H"_2 "O" → "NaOH"+ "H"_2`
Balance the following equation. Also name the product formed.
`"Zn" + "HCI" → "ZnCI" _2 + "H"_2`
Write the chemical equation for the following word equation and balance them.
Calcium oxide + Carbon dioxide → Calcium carbonate
Balance the following equation:
PbO + NH3 → Pb + H2O + N2
Balance the following equation:
PbS + O2 → PbO + SO2
Balance the following equation:
HNO3 + H2S → NO2 + H2O + S
Answer the following question.
What is observed when 2 mL of dilute hydrochloric acid is added to 1 g of sodium carbonate taken in a clean and dry test tube? Write a chemical equation for the reaction involved.
Give word equation for the following chemical reaction and give the names of the product formed.
NH3 + HCl→ NH4Cl
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↓
What is a chemical equation?
What are the steps involved in writing the skeletal equation?
