Advertisements
Advertisements
प्रश्न
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.
Advertisements
उत्तर
Change of colour — In certain chemical reactions a change of colour is seen to be observed. Heat on substances to observe change in colour of reactants and products.
Heat on:
Mercury [II] oxide 2HgO → 2Hg + O2 [g]
Colour change:
Mercury [II] oxide [HgO] – Red – to Mercury [Hg] – Silvery
APPEARS IN
संबंधित प्रश्न
Balance the following equation and add state symbols:
Zn + HCI → ZnCI2 + H2
Give one example of an exothermic reaction.
Write word equation for the following skeletal equation:
\[\ce{AgBr -> Ag + Br2}\]
Balance the following equation. Also name the product formed.
`"H"_2 +"CI"_2 → "HCI"`
Complete the following equation:
CH2 + H5OH `("Hot Conc." H_2SO_4)/`>
Balance the following equation:
Pb3O4 → PbO + O2
Balance the following equation:
NaHCO3 → Na2CO3 + H2O + CO2
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?
\[\ce{2KClO3->[MnO2] 2KCl + 3O2[g] - is a balanced equation.}\]
State why the compound MnO2 is written above the arrow.
Balance the given chemical reaction as per the instructions below.
\[\ce{NaOH + H2SO4 -> Na2SO4 + H2O}\]
Make a list of the elements in the chemical equation.
