Advertisements
Advertisements
प्रश्न
A colourless lead salt, when heated, produces a yellow residue and brown fumes.
(a) Name the lead salt.
(b) Name the brown fumes.
(c) Write a chemical equation of the reaction involved.
Advertisements
उत्तर
(a) Lead salt is lead nitrate.
(b) The brown fumes is nitrogen dioxide gas.
(c) The chemical reaction is given as follows:
2Pb(NO3)2 (s) → 2PbO (s) + 4NO2 (g) + O2 (g)
APPEARS IN
संबंधित प्रश्न
Why should a magnesium ribbon be cleaned before it is burnt in air?
Balance the following chemical equation.
\[\ce{NaCl + AgNO3 -> AgCl + NaNO3}\]
Translate the following statement into chemical equation and then balance it.
Potassium metal reacts with water to give potassium hydroxide and hydrogen gas.
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.
Write complete balanced equation for the following reaction:
Calcium (solid) + water (liquid) 
Calcium Hydroxide (solution) + Hydrogen (gas)
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.
Substitute formulae for names and balance the following equation:
Calcium carbonate reacts with hydrochloric acid to produce calcium chloride, water and carbon dioxide gas.
Balance the following chemical equation:
The removal of oxygen from a substance is called:
(a) oxidation
(b) corrosion
(c) reduction
(d) rancidity
Write your observation for the following chemical reaction and name the product formed:
When sugar is heated.
Write your observation for the following chemical reaction and name the product formed :
When ammonium chloride is heated with sodium hydroxide.
Write symbolic representation for the following word equation and balance them :
Calcium oxide + Water → Calcium hydroxide
Balance the following equation:
Pb3O4 → PbO + O2
Complete the following blank in the equation as indicated.
\[\ce{CaH2_{(s)} + 2H2O_{( aq)}-> Ca(OH)2_{(s)} + 2H2_{(g)}}\]
Moles: 1 mole + ______ `→` ______ + ______
\[\ce{MnO2 + 4HCl -> MnCl2 + 2H2O + Cl2}\]
0.02 moles of pure MnO2 is heated strongly with conc. HCl. Calculate moles of salt formed.
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.
Explain the term ‘chemical equation’.
\[\ce{2KClO3->[MnO2] 2KCl + 3O2[g] - is a balanced equation.}\]
Give a reason why the above equation is balanced.
Balance the following simple equation:
H2 + Cl2 → HCl
Underline the compound in the equation given below, it is incorrectly balanced and write the correct balancing for the same.
3CuO + NH3 → 3Cu + 3H2O + N2
