Advertisements
Advertisements
Question
Explain with the help of balanced equations, how precipitation reactions are used for identifying the positive radicals in three different salts, each having a different cation [positive ion].
Solution
Precipitation reactions are used to identify the positive ions from their colours.
\[\ce{CuSO4 + 2NaOH->Na2SO4 + \underset{\text{pale blue ppt.}}{Cu[OH]2 v}}\]
identified ion is \[\ce{Cu^2+}\]
\[\ce{FeCl3 + 3NaOH->3NaCl + \underset{\text{reddish brown ppt.}}{Fe[OH]3 v}}\]
identified ion is \[\ce{Fe^3+}\]
\[\ce{Pb[NO3] + 2NaOH->2NaNO3 + \underset{\text{chalky white ppt.}}{Pb[OH]2 v}}\]
identified ion is \[\ce{Pb^2+}\]
APPEARS IN
RELATED QUESTIONS
How do the following help in bringing about a chemical change?
light.
Define catalyst.
MULTIPLE CHOICE QUESTIONS
Tick the most appropriate answer.
Reduction reaction is the exact opposite of
- displacement reaction
- decomposition reaction
- oxidation reaction
- none of these
MULTIPLE CHOICE QUESTIONS
Tick the most appropriate answer.
Compounds, which in their molten state allow an electric current to pass through them are called
- electrolytes
- non-electrolytes
- non-conductors
- none of these
FILL IN THE BLANK
The new substances formed during a chemical reaction are called the ..................
What are chemical reactions?
Name three reducing agents ?
Explain the following reaction with one suitable example of Double decomposition reaction.
Name the type of chemical reaction shown by the following equation:
Fe + CuSO4 → FeSO4 + Cu
Name the type of chemical reaction shown by the following equation :
Fe2O3 + 2Al → Al2O3 + 2Fe
Complete the statement by filling the gaps using appropriate term from the terms given in the bracket.
(slow, coloured, arrow, fast, smell, milky, physical, product, chemical, reactant, covalent, ionic, octet, duplet, exchange, sharing, equality sign)
Rusting of iron is a ______ chemical change.
Complete the statement by filling the gaps using appropriate term from the terms given in the bracket.
(slow, coloured, arrow, fast, smell, milky, physical, product, chemical, reactant, covalent, ionic, octet, duplet, exchange, sharing, equality sign)
The spoiling of food is a chemical change which is recognized from the generation of certain ______ due to it.
Complete the statement by filling the gaps using appropriate term from the terms given in the bracket.
(slow, coloured, arrow, fast, smell, milky, physical, product, chemical, reactant, covalent, ionic, octet, duplet, exchange, sharing, equality sign)
Oxygen is a ______ in respiration.
Explain,giving one example of the following chemical changes:
Reversible reaction
Distinguish by heating the following in dry test tubs.
Zinc nitrate and copper nitrate.
The changes in which new substance with new chemical properties are formed are ______.
Water boiling into water vapour is an example of chemical change.
If you leave a piece of iron in the open for a few days, it acquires a film of brownish substance, called rust.
Do you think the formation of rust from iron is a chemical change?
Magnesium + oxygen → magnesium oxide.
2Mg + O2 → 2Mg O
Write a note on the following:
Fermentation
