Advertisements
Advertisements
प्रश्न
Explain the need of the term average atomic mass.
Advertisements
उत्तर
- Several naturally occurring elements exist as a mixture of two or more isotopes.
- Isotopes have different atomic masses.
- The atomic mass of such an element is the average of atomic masses of its isotopes.
- For this purpose, the atomic masses of isotopes and their relative percentage abundances are considered.
Hence, the term average atomic mass is needed to express the atomic mass of elements containing a mixture of two or more isotopes.
APPEARS IN
संबंधित प्रश्न
The number of molecules in 22.4 cm3 of nitrogen gas at STP is ______.
Which of the following has the largest number of atoms?
Calculate the molecular mass of the following in u.
NH3
Solve problem:
Calculate the number of an atom of the following (Given: Atomic mass of I = 127 u).
254 u of iodine (I)
Solve problem:
Calculate the number of an atom of the following (Given: Atomic mass of I = 127 u).
254 g of iodine (I)
Solve problem:
Arjun purchased 250 g of glucose (C6H12O6) for Rs 40. Find the cost of glucose per mole.
Solve the problem:
The natural isotopic abundance of 10B is 19.60% and 11B is 80.40 %. The exact isotopic masses are 10.13 and 11.009 respectively. Calculate the average atomic mass of boron.
Solve problem:
Calculate the number of atoms of the following. (Average atomic mass : N = 14 u, S = 32 u)
0.4 mole of nitrogen
Solve problem:
Calculate the number of atoms of the following. (Average atomic mass : N = 14 u, S = 32 u)
1.6 g of sulfur
Solve problem:
Calculate the number of moles of magnesium oxide, MgO in
- 80 g, and
- 10 g of the compound.
(Average atomic masses of Mg = 24 and O = 16)
An element X has the following isotopic composition 200X = 90%, 199X = 8% and 202X = 2%. The weighted average atomic mass of the element X is closest to
Two 22.4 litre containers A and B contains 8 g of O2 and 8 g of SO2 respectively at 273 K and 1 atm pressure, then
What is the mass of precipitate formed when 50 ml of 8.5% solution of AgNO3 is mixed with 100 ml of 1.865% potassium chloride solution?
Which of the following is/are true with respect to carbon-12.
Define relative atomic mass.
Calculate the average atomic mass of naturally occurring magnesium using the following data.
| Isotope | Isotopic atomic mass | Abundance (%) |
| Mg24 | 23.99 | 78.99 |
| Mg25 | 24.99 | 10.00 |
| Mg26 | 25.98 | 11.01 |
The reaction between aluminium and ferric oxide can generate temperatures up to 3273 K and is used in welding metals.
(Atomic mass of Al = 27 u Atomic mass of O = 16 u)
\[\ce{2Al + Fe2O3 -> Al2O3 + 2Fe}\]; If, in this process, 324 g of aluminium is allowed to react with 1.12 kg of ferric oxide.
- Calculate the mass of Al2O3 formed.
- How much of the excess reagent is left at the end of the reaction?
An element has a bee structure with cell edge of 288 pm. The density of element is 7.2 g cm-3. What is the atomic mass of an element?
Boron has two isotopes 10B and 11B with atomic masses 10 and 11, respectively. If its average atomic mass is 10.81, the abundance of 10B is ____________.
How many moles of ammonia are present in 5.6 cm3 of ammonia gas at STP?
What is the average mass of an element if it has two isotopes, one of mass 6.015 u with 8.24 % and other of mass 7.016 u with 91.26% respectively?
It is found that in 11.2 L at 0°C and 1 atm, of any gaseous compound of 'X', there is never less than 15.5 gm of 'X'. It is also found that 11.2 L of vapours of 'X' at 0°C and 1 atm, weighs 62 gm. The atomicity of 'X' is ______.
0.05 F electricity is passed through CuSO4 solution. Calculate the mass of Cu produced at cathode? (molar mass of Cu = 63.5 g mol-1)
