Advertisements
Advertisements
Question
Calculate the molecular mass of the following in u.
NH3
Solution
Molecular mass of NH3 = (1 × Average atomic mass of N) + (3 × Average atomic mass of H)
= (1 × 14.0 u) + (3 × 1.0 u)
= 17 u
The molecular mass of NH3 = 17 u
APPEARS IN
RELATED QUESTIONS
The number of molecules in 22.4 cm3 of nitrogen gas at STP is ______.
Calculate the molecular mass of the following in u.
CH3COOH
Calculate the molecular mass of the following in u.
C2H5OH
What is the ratio of molecules in 1 mole of NH3 and 1 mole of HNO3?
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 g of iodine (I)
Solve problem:
Arjun purchased 250 g of glucose (C6H12O6) for Rs 40. Find the cost of glucose per mole.
Solve 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)
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)
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)
Explain the need of the term average atomic mass.
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
Which one of the following represents 180 g of water?
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.
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 ____________.
The unit of atomic mass, amu is replaced by u, here u stands for ______.
One amu is equal to ________.
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)
