Question

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?

July 1, 2024

Answer

One gram of gold sample will contain 90/100 = 0.9 g of gold

Number of moles of gold = Mass of gold / Atomic mass of gold

= 0.9/197

= 0.0046

One mole of gold contains NA atoms = 6.022 x 10²³

∴ 0.0046 mole of gold will contain = 0.0046 × 6.022 × 10²³

= 2.77 x 10²¹atoms

💡 Some Related Questions

The acid which contains four hydrogen atoms —
(a) Formic acid
(b) Sulphuric acid
(c) Nitric acid
(d) Acetic acid

What is the term defined : i) A base which is soluble in water.

A health food store has a large display of bracelets made of copper metal. The storekeeper claims that the copper atoms from the bracelet diffuse into the body and the wearer is protected against rheumatoid diseases. Kuber wants to buy a bracelet for his grandmother who is suffering from arthritis. But his friend Ramesh suggests him against it. He says that it is a superstitious belief and wearing any metal on the body does not cure someone of the disease. Answer the following questions based on the above information: (𝒊) Do you think that Kuber should agree to Ramesh’s advice and not buy the bracelet? Give one reason. (𝒊𝒊) What values are displayed by Ramesh through his suggestion? (𝒊𝒊𝒊) Suggest one activity to promote these values.

Calculate the number of electrons present in 15.4 of carbon tetrachloride CCl4

You are provided with a fine white coloured powder which is either sugar or salt. How would you identify it without tasting?

What is the fraction of the mass of water due to neutrons?

A big drop has volume 1.0 mL. How many molecules of water are there is this drop, If the density of water is 1g/mL?

A colorless liquid is thought to be a pure compound. Analysis of three samples of the material yield the following results.
Mass of Sample Mass of carbon Mass of Hydrogen
Sample 1 1.0 g 0.862 g 0.138 g
Sample 2 1.549 g 1.335 g 0.214 g
Sample 3 0.988 g 0.852 g 0.136 g

Could the material be a pure compound?

Calculate the ratio between the mass of one atom of hydrogen and mass of one atom of silver.

In photosynthesis, 6 molecules of carbon dioxide combine with an equal number of water molecules through a complex series of reactions to give a molecule of glucose having a molecular formula C6H12O6. How many grams of water would be required to produce 18 g of glucose? Compute the volume of water so consumed assuming the density of water to be 1g cm-3.