Question

Chemists use the mole as the unit for the amount of substance. One mole is equal to 6.02 x 10^23 (just like one dozen is equal to 12). A 40.1 g sample of calcium contains approximately 1 mole of calcium atoms. How many calcium atoms are in a 4 kg sample of calcium?

Answer 1

Answer:

$atoms=6.0x10^{25}atoms$

Explanation:

Hello!

In this case, since we are given 4 kg of a calcium-containing sample, in order to compute the atoms there first need to compute the mass in grams:

$m=4kg*\frac{1000g}{1kg} =4000g$

Next, via the molar mass and the Avogadro's number, we can compute the atoms as follows:

$atoms=4000g*\frac{1mol}{40.1g}*\frac{6.02x10^{23}atoms}{1mol}\\\\atoms=6.0x10^{25}atoms$

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