PiperRockelle13
contestada

Shalom, Guys!
The molar mass of strontium (\ce{Sr}SrS, r) is \pu{87.62 g/mol}87.62 g/mol87, point, 62, space, g, slash, m, o, l. Calculate the number of atoms in a \pu{67.5 mg}67.5 mg67, point, 5, space, m, g sample of \ce{Sr}SrS, r. Write your answer in scientific notation using three significant figures. \text{atoms Sr} ______________ atoms Sr
Love, Piper Rockelle

Respuesta :

keziakh004

Answer:

4.30 × 10²⁰ atoms

Explanation:

You need to find out how many moles you have.  First, convert milligrams to grams.

62.5 mg × (1 g)/(1000 mg) = 0.0625 g

Next, use the molar mass to convert from grams to moles.

0.0625 g ÷ 87.62 g/mol = 7.13 × 10⁻⁴ mol

To convert from moles to atoms, you need to use Avogadro's number (6.022 × 10²³).  Avogadro's number is the number of atoms in a mole.

7.13 × 10⁻⁴ mol × 6.022 × 10²³ atoms/mol = 4.296 × 10²⁰ ≈ 4.30 × 10²⁰ atoms

You will have 4.30 × 10²⁰ atoms of strontium.

The number of Strontium atoms are 4.30 × 10²⁰ atoms

Given:

Mass of Strontium = 62.5 mg × (1 g)/(1000 mg) = 0.0625 g

Molar mass of Strontium = 87.62 g/mol

To find:

Moles of Strontium = ?

Number of moles:

It is defined as given mass over molar mass.

[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}\\\\\text{Number of moles}=\frac{0.0625 g}{87.62 g/mol }\\\\\text{Number of moles}=7.13 * 10^{-4} mol[/tex]

Avogadro's number is the number of atoms in a mole (6.022 * 10²³)

Conversion of moles into atoms:

[tex]7.13 × 10^{-4} mol * 6.022 * 10^{23} atoms/mol \\\\\text{ Sr atoms}= 4.296 * 10^{20} = 4.30 * 10^{20} atoms[/tex]

Thus, Strontium atoms will be 4.30 × 10²⁰ atoms.

Find more information about Number of moles here:

brainly.com/question/15356425

Otras preguntas

Q&A Education