Advertisements
Advertisements
Question
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.
Solution
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:
Zinc carbonate ZnCO3 → ZnO + CO2 [g]
Colour change:
Zinc carbonate [ZnCO3] – White – to Zinc oxide [ZnO] – Yellow (when hot)
APPEARS IN
RELATED QUESTIONS
Why should a magnesium ribbon be cleaned before it is burnt in air?
2 mL of sodium hydroxide solution is added to a few pieces of granulated zinc metal taken in a test tube. When the contents are warmed, a gas evolves which is bubbled through a soap solution before testing. Write the equation of the chemical reaction involved and the test to detect the gas. Name the gas which will be evolved when the same metal reacts with dilute solution of a strong acid.
What is a chemical equation? Explain with the help of an example.
Balance the following equation .
N2 + O2 → NO
Balance the following equation. Also name the product formed.
`"KCIO"_3 → "KCI" +"O"_2`
Explain the terms with examples.
Balanced equation
Write the chemical equation for the following word equation and balance them.
Magnesium + Sulphuric acid → Magnesium sulphate + Hydrogen
Give one example in the case where supplying energy [given below] is necessary for a chemical reaction.
Pressure
\[\ce{2KClO3->[MnO2] 2KCl + 3O2[g] - is a balanced equation.}\]
State what is a ‘balanced equation’.
Balance the following simple equation:
Fe + Cl2 → FeCl3
