Advertisements
Advertisements
प्रश्न
A gold sample contains 90% of gold and the rest copper. How many atoms of gold are present in one gram of this sample of gold?
Advertisements
उत्तर
1 g of gold sample contains = `90/100`
= 0.9g gold
Number of moles of gold = `"Mass of gold"/"Atomic mass of gold"`
= `0.9/197`
= 0.0046
1 mole of gold contains = 6.022 × 1023 atoms
0.0046 mole of gold = 6.022 × 1023 × 0.0046
= 2.77 × 1021 atoms
APPEARS IN
संबंधित प्रश्न
The number of electrons in an ion Y2+ is 10. The atomic number of element Y is most likely to be :
What is the numerical value of Avogadro number ?
What name is given to the number 6.022 × 1023 ?
What is the number of molecules in 1.5 moles of ammonia ?
Calculate the number of molecules in 4 g of oxygen.
If 32 g of sulphur has x atoms, then the number of atoms in 32 g of oxygen will be :
If 12 gram of carbon has x atoms, then the number of atoms in 12 grams of magnesium will be :
What weight of oxygen gas will contain the same number of molecules as 56 g of nitrogen gas ?
(O = 16 u ; N = 14 u)
What mass of nitrogen, N2, will contain the same number of molecules as 1.8 g of water, H2O ?
(Atomic masses : N = 14 u ; H = 1 u ; O = 16 u)
How many grams of magnesium will have the same number of atoms as 6 grams of carbon ?
(Mg = 24 u ; C = 12 u )
The mass of one atom of an element X is 2.0 × 10–23 g.
Calculate the atomic mass of element X.
What could element X be ?
Which has more number of atoms?
100g of N2 or 100 g of NH3
Compute the difference in masses of one mole each of aluminium atoms and one mole of its ions. (Mass of an electron is 9.1×10–28 g). Which one is heavier?
A silver ornament of mass ‘m’ gram is polished with gold equivalent to 1% of the mass of silver. Compute the ratio of the number of atoms of gold and silver in the ornament.
. A sample of ethane (C2H6) gas has the same mass as 1.5 ×1020 molecules of methane (CH4). How many C2H6 molecules does the sample of gas contain?
In the atom of an element X, 6 electrons are present in the outermost shell. If it acquires noble gas configuration by accepting requisite number of electrons, then what would be the charge on the ion so formed?
Helium atom has 2 electrons in its valence shell but its valency is not 2, Explain
An element X has a mass number 4 and atomic number 2. Write the valency of this element?
