Advertisements
Advertisements
प्रश्न
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.
Advertisements
उत्तर
| Isotope | % Abundance | Mass (u) |
| ¹⁰B | 19.60% | 10.13 u |
| ¹¹B | 80.40% | 11.009 u |
Convert % to fractional abundance
For ¹⁰B: 19.60% = 0.1960
For ¹¹B: 80.40% = 0.8040
Apply formula for average atomic mass
Average atomic mass = (f1 × m1) + (f2 × m2)
= (0.1960 × 10.13) + (0.8040 × 11.009)
0.1960 × 10.13 = 1.98648
0.8040 × 11.009 = 8.84724
1.98648 + 8.84724 = 10.83372
Average atomic mass of boron = 10.83u (approx.)
APPEARS IN
संबंधित प्रश्न
Choose the correct option.
Which of the following has maximum number of molecules?
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:
The mass of an atom of hydrogen is 1.008 u. What is the mass of 18 atoms of hydrogen?
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.
24 g of carbon reacts with some oxygen to make 88 grams of carbon dioxide. Find out how much oxygen must have been used.
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 moles of magnesium oxide, MgO in
- 80 g, and
- 10 g of the compound.
(Average atomic masses of Mg = 24 and O = 16)
Calculate the number of atoms of hydrogen present in 5.6 g of urea, \[\ce{(NH2)2CO}\]. Also calculate the number of atoms of N, C, and O.
Solve problem:
Calculate the mass of sulfur dioxide produced by burning 16 g of sulfur in excess of oxygen in the contact process. (Average atomic mass : S = 32 u, O = 16 u)
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
Which one of the following is used as a standard for atomic mass.
Define relative atomic mass.
The unit of atomic mass, amu is replaced by u, here u stands for ______.
A 100 g of sample of haemoglobin on analysis was found to contain 0.34% Fe by mass. If each haemoglobin molecule has four Fe2+ ions, the molecular mass of haemoglobin is: (Fe = 56 amu)
Which symbol replaces the unit of atomic mass, amu?
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)
