Advertisements
Advertisements
प्रश्न
Define the term Relative molecular mass. State why indirect methods are utilised to determine the absolute mass of an atom. Explain in brief the indirect method used.
Advertisements
उत्तर
Relative molecular mass [RMM] of an element/compound : “Is the number of times one molecule of the substance is heavier than 1/12 the mass of an atom of carbon [C12].
RAM = `"Mass of one atom of the element"/("Mass of one atom of carbon"["C"^12])`
OR
“Mass of one molecule as compared with the 1/12 mass of an atom of carbon[C12]”
RMM = `("Mass of one molecule of the substance")/((1/2) "Mass of one atom of carbon"["C"^12])`
To determine the absolute mass of an atom indirect methods are utilised as Atom are extremely small and very light.
An isotope of carbon C12 [carbon -12 atom] has been assigned an atomic mass of exactly 12 atomic mass units] is used.
APPEARS IN
संबंधित प्रश्न
What is meant by a chemical formula ? Write the formulae of one element and one compound.
The element having atomicity 'four' is most likely to be :
Name the following compounds. Also write the symbols/formulae of the ions present in them :
- CuSO4
- (NH4)2SO4
- Na2O
- Na2CO3
- CaCl2
Fill in the blank:
Formula of iron (ill) carbonate is _____ .
Correct the following statement:
A molecular formula represents an element.
Give the empirical formula of : Benzene C6H6
Identify the following substance:
An alkaline gas A which gives dense white fumes with hydrogen chloride.
The formula of the nitride of a metal X is XN, state the formula of :
- its sulphate
- its hydroxide.
Name the element in the compound and give the formula of the following compound:
Blue vitriol
Write the formula of the following compound:
Potassium iodide
Write the formula of the following compound:
Sodium bisulphite
Write the formula of the following compound:
Calcium bisulphite
Write the formula of the following compound:
Lead [II] oxide
State of the following formula of a compound is incorrect. Incorrectly write the correct formula.
KCr2O7
State of the following formula of a compound is incorrect. Incorrectly write the correct formula.
BaCl2
Write the chemical formula for the following compounds
- Aluminium sulphate
- Silver nitrate
- Magnesium oxide
- Barium chloride
Which of the following represents a correct chemical formula? Name it.
Which of the following represents a correct chemical formula? Name it.
BiPO4
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.
