Advertisements
Advertisements
प्रश्न
The visible universe is estimated to contain 1022 stars. How many moles of stars are present in the visible universe?
उत्तर
1 mole of stars = 6.022 × 1023 stars
Number of moles of stars = `10^22/(6.023 xx 10^22)`
= 0.0166 moles
APPEARS IN
संबंधित प्रश्न
Calculate the molar mass of the following substance:
Sulphur molecule, S8
Calculate the molar mass of the following substance:
Nitric acid, HNO3
How many moles of oxygen atoms are present in one mole of the following compounds ?
- Al2O3
- CO2
- Cl2O7
- H2SO4
- Al2(SO4)3
Define the term.
Molar volume
Calculate the number of molecules in 12.8g of sulphur dioxide gas. Take Avogadro's number as 6 x 1023.
[S = 32, 0 = 16 ]
Complete the following calculations. Show working for complete credit :
Calculate the mass of calcium that will contain the same number of atoms as are present in 3.2 gm of Sulphur. [Atomic masses : S = 32, Ca = 40]
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]
How many grams of HCl are present in 0.1 mole of it?
1 mole of any substance contains ______ molecules.
Cinnabar (HgS) is a prominent ore of mercury. How many grams of mercury are present in 225 g of pure HgS? Molar mass of Hg and S are 200.6 g mol–1 and 32 g mol–1 respectively.