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प्रश्न
Write the formula of the following compound:
Iron [III] sulphate
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उत्तर
Iron [III] sulphate - Fe2[SO4]3 - `"Fe"^(3+)"SO"_4^(2-)`
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संबंधित प्रश्न
Fill the following blanks with suitable words :
In a chemical reaction, the sum of the masses of the reactants and the products remains unchanged. This is called ....................
What do the following abbreviations stand for ?
- O
- 2O
- O2
- 3O2
What do the symbols, H2, S and O4 mean in the formula H2SO4 ?
Name the following compounds. Also write the symbols/formulae of the ions present in them :
- CuSO4
- (NH4)2SO4
- Na2O
- Na2CO3
- CaCl2
An element A forms an oxide A2O5.
What will be the formula of chloride of A ?
The formula of carbonate of a metal M is M2CO3.
What will be the formula of its iodide ?
Identify the following substance:
An alkaline gas A which gives dense white fumes with hydrogen chloride.
Name the element in the compound and give the formula of the following compound:
Ethane
Write the formula of the following compound:
Potassium zincate
Write the formula of the following compound:
Potassium plumbite
Write the formula of the following compound:
Sodium chloride
Write the formula of the following compound:
Copper [II] chloride
Write the formula of the following compound:
Tetra amine copper [II] sulphate
Define the term Relative atomic mass. State why indirect methods are utilised to determine the absolute mass of an atom. Explain in brief the indirect method used.
State of the following formula of a compound is incorrect. Incorrectly write the correct formula.
NaClO
Write the molecular formulae for the following compounds
Copper (II) bromide
Complete the following crossword puzzle (Fig. 3.1) by using the name of the chemical elements. Use the data given in Table.
| Across | Down | ||
| 2 | The element used by Rutherford during his α–scattering experiment | 1 | A white lustrous metal used for making ornaments and which tends to get tarnished black in the presence of moist air |
| 3 | An element which forms rust on exposure to moist air | 4 | Both brass and bronze are alloys of the element |
| 5 | A very reactive non–metal stored under water | 6 | The metal which exists in the liquid state at room temperature |
| 6 | Zinc metal when treated with dilute hydrochloric acid produces a gas of this element which when tested with burning splinter produces a pop sound. | 8 | An element with symbol Pb |
Play a game for writing formula.
Example 1: Make placards with symbols and valencies of the elements separately. Each student should hold two placards, one with the symbol in the right hand and the other with the valency in the left hand. Keeping the symbols in place, students should criss-cross their valencies to form the formula of a compound.
Play a game for writing formula.
Example 2: A low-cost model for writing formulae: Take empty blister packs of medicines. Cut them in groups according to the valency of the element, as shown in the figure. Now, you can make formulae by fixing one type of ion into other.
For example:
The formula for sodium sulphate:
2 sodium ions can be fixed on one sulphate ion.
Hence, the formula will be Na2SO4.
Do it yourself:
Now, write the formula of sodium phosphate.
