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How many atoms of copper are in 0.125g of copper

User Mike Edwards
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1 Answer

15 votes
15 votes

Answer:

1.19 x 10²¹ atoms of Cu (copper).

Step-by-step explanation:

What is given?

Mass of copper (Cu) = 0.125 g.

Molar mass of Cu = 63.5 g/mol.

Avogadro's number = 6.022 x 10²³ atoms/mol.

Step-by-step solution:

First, let's convert 0.125 g of Cu to moles using its molar mass, like this:


0.125\text{ g Cu}\cdot\frac{1\text{ mol Cu}}{63.5\text{ g Cu}}=0.00197\text{ moles Cu.}

And now, let's use the Avogadro's number, which is telling us that there are 6.022 x 10²³ atoms of a certain element in 1 mol. The conversion will look like this:


0.00197\text{ moles Cu}\cdot\frac{6.022\cdot10^(23)\text{ atoms}}{1\text{ mol}}=1.19\cdot10^(21)\text{ atoms Cu.}

The answer is that we have 1.19 x 10²¹ atoms of Cu (copper) in 0.125 g of Cu (copper).

User Napfernandes
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