Question

How many atoms are in 8.00 moles of potassium chromate?​

Answer 1

Answer:

$\boxed {\boxed {\sf About \ 4.82 *10^{24} \ atoms \ K_2CrO_4}}$

Explanation:

To convert from moles to atoms, Avogadro's Number must be used.

• $6.022*10^{23}$

This number tells us how many particles (atoms, molecules, ions. etc.) in 1 mole of a substance. In this case, it is atoms of potassium chromate (K₂CrO₄) in 1 mole.

$6.022*10^{23} \ atoms \ K_2CrO_4 / 1 \ mol \ K_2CrO_4$

Use this number as a fraction.

$\frac{6.022*10^{23} \ atoms \ K_2CrO_4}{1 \ mol \ K_2CrO_4}$

Multiply by the given number of moles (8.00).

$8.00 \ mol \ K_2CrO_4 *\frac{6.022*10^{23} \ atoms \ K_2CrO_4}{1 \ mol \ K_2CrO_4}$

The moles of potassium chromate will cancel.

$8.00 *\frac{6.022*10^{23} \ atoms \ K_2CrO_4}{1}$

The denominator of 1 can be ignored.

$8.00 *(6.022 *10^{23} \ atoms \ K_2CrO_4)$

Multiply.

$4.8176*10^{24} \ atoms \ K_2CrO_4$

The original measurement of moles (8.00) has 3 significant figures, so we must round our answer to 3 sig figs.

For the number we calculated, that is the hundredth place. The 7 in the thousandth place tells us to round the 1 up to a 2.

$4.82 *10^{24} \ atoms \ K_2CrO_4$

There are about 4.82* 10²⁴ atoms of potassium chromate in 8.00 moles.

Answer 2

Answer:

481.6x10^23

Explanation: