Question

How many moles of Fe contains 3.41 x 1023 Fe atoms?

Answer 1

Answer:

Explanation:

28个

Answer 2

Answer:

$\boxed {\boxed {\sf 0.566 \ mol \ Fe}}$

Explanation:

We are asked to convert a number of atoms to moles.  

We can convert atoms to moles using Avogadro's Number, which is 6.022 × 10²³. This is the number of particles (atoms, molecules, formula units, etc.) in 1 mole of a substance. In this problem, the particles are atoms of iron (Fe). There are 6.022 ×10²³ atoms of iron in 1 mole of iron.  

We use dimensional analysis to convert atoms to moles. This involves setting up ratios. Use Avogadro's Number and the underlined information to make a ratio.

$\frac {6.022 \times 10^{23}\ atoms \ Fe}{1 \ mol \ Fe}$

We are converting 3.41 × 10²³ atoms of iron to moles, so we multiply by this value.

$3.41 \times 10^{23} \ atoms \ Fe *\frac {6.022 \times 10^{23}\ atoms \ Fe}{1 \ mol \ Fe}$

Flip the ratio. It stays equivalent, but it allows the units of atoms of iron to cancel.

$3.41 \times 10^{23} \ atoms \ Fe *\frac{1 \ mol \ Fe} {6.022 \times 10^{23}\ atoms \ Fe}$

$3.41 \times 10^{23}*\frac{1 \ mol \ Fe} {6.022 \times 10^{23}}$

$\frac{3.41 \times 10^{23}} {6.022 \times 10^{23}} \ mol \ Fe$

$0.5662570575\ mol \ Fe$

The original measure ment of iron atoms ( 3.41 × 10²³ ) has 3 significant figures, so our answer must have the same. For the number we calculated, that is the thousandths place. The 2 in the ten-thousandths place ( 0.5662570575) tells us to leave the 6 in the thousandths place.

$0.566 \ mol \ Fe$

3.41 × 10²³ atoms of iron is equal to approximately 0.566 moles of iron.