Question

Help asap. How many moles are 5.55x10^25 atoms of Mg

Answer 1

Answer:

$\boxed {\boxed {\sf About \ 92.2 \ moles \ of \ Magnesium}}$

Explanation:

To convert from atoms to moles, we must Avogadro's number:

• 6.022*10²³

This number tells us the amount of particles (atoms, molecules, etc.) in 1 mole of a substance. In this case, it is atoms of magnesium in 1 mole.

• 6.022 *10²³ atoms Mg / 1 mol mg

Now, let's set up an expression using:

$\frac {6.022 * 10^ {23} \ atoms \ Mg}{ 1 \ mol \ Mg}$

Multiply this by the given number of atoms.

$5.55*10^{25} \ atoms \ Mg *\frac {6.022 * 10^ {23} \ atoms \ Mg}{ 1 \ mol \ Mg}$

Flip the fraction so the atoms of magnesium can cancel.

$5.55*10^{25} \ atoms \ Mg *\frac { 1 \ mol \ Mg }{6.022 * 10^ {23} \ atoms \ Mg}$

$5.55*10^{25} *\frac { 1 \ mol \ Mg }{6.022 * 10^ {23}}$

Multiply and condense this into 1 fraction.

$\frac { 5.55*10^{25} \ mol \ Mg }{6.022 * 10^ {23}}$

$92.1620724 \ mol \ Mg$

The original measurement had 3 significant figures, so our answer must have that many as well. For the number we calculated, that is the tenth place. The 6 in the hundredth place tells us to round the 1 to a 2.

$92.2 \ mol \ Mg$

It is about 92.2 moles of magnesium.