Advertisements
Advertisements
Question
Deduce the number of molecules of the following compound in the given quantity.
90g water
Advertisements
Solution
Number of moles in water = `"Mass of water in grams"/"Molecular mass of water"`
= `90/18`
= 5 moles
∴ 5 moles of H2O contains = 5 × 6.022 × 1023 molecules = 30.11 × 1023 molecules.
The number of molecules in 90 grams of water is 3.01 × 1024.
APPEARS IN
RELATED QUESTIONS
Fill in the following blanks :
A mole represents an .............. number of particles of a substance.
Fill in the following blanks :
64 g of oxygen gas contains ................ moles of oxygen atoms.
What weight of each element is present in 1.5 moles of sodium sulphite, Na2SO3 ?
(Atomic masses : Na = 23 u ; S = 32 u ; O = 16 u)
What is meant by ‘a mole of carbon atoms’ ?
Explain with examples what is meant by a 'mole' of a substance.
The relative atomic mass of Cl atom is 35.5 a.m.u. Explain this statement.
A sample of ammonium nitrate when heated yields 8.96 litres of steam (measured at STP)
NH4NO3 → N2O + 2H2O
What mass of ammonium nitrate should be heated to produce 8.96L of steam?
A sample of ammonium nitrate when heated yields 8.96 litres of steam (measured at STP)
NH4NO3 → N2O + 2H2O
Determine the percentage of oxygen in the ammonium nitrate?
Consider the following reaction and based on the reaction answer the questions that follow :
\[\ce{(NH4)2Cr2O7 ->[heat] N2(g) + 4H2O(g) + Cr2O3}\]
Calculate :
(i) The quantity in moles of (NH4)2Cr2O7 if 63 gm of (NH4)2Cr2O7 is heated.
(ii) The quantity in moles of nitrogen formed.
(iii) The volume in litres or dm3 of N2evolved at STP.
(iv) The mass in grams of Cr2O3 formed at the same time
[Atomic masses : H = 1, Cr=52, N=14]
Define the term:
Gram atom
How many grams of HCl are present in 0.1 mole of it?
How many grams of CO2 is present in 0.1 mole of it?
Determine the number of molecules in a drop of water which weighs 0.09 g.
Four grams of caustic soda contains ______.
Calculate the number of oxygen atoms in 0.10 mole of Na2CO3 . 10H2O.
Match the following.
| 1. | 8 g of O2 | - | 4 moles |
| 2. | 4 g of H2 | - | 0.25 moles |
| 3. | 52 g of He | - | 2 moles |
| 4. | 112 g of N2 | - | 0.5 moles |
| 5. | 35.5 g of Cl2 | - | 13 moles |
How many grams are there in the following?
4 moles of the phosphorous molecule, P4
Raunak took 5 moles of carbon atoms in a container and Krish also took 5 moles of sodium atoms in another container of same weight.
- Whose container is heavier?
- Whose container has more number of atoms?
