Question

What is the mass of 1.20×10*24 atoms of sodium

Answer 1

Answer:

Number of atoms of sodium (Na) = 1.20 X 10²⁴ atoms

Avogadro's number (NA) = 6.022 X 10²³ atoms

Mass of Na = ??

Explanation:

As we know that mass can be calculated by formula

No. of Moles Na = mass of Na/ Molecular mass of Na

therefore, for calculating mass of Na we need number of moles of Na,

1 mol of Na contains  = 6.022 X 10²³ atoms

x mol of Na contains  = 1.20 X 10²⁴ atoms

No. of moles of Na = (1.20 X 10²⁴ atoms X 1 mol of Na ) / 6.022 X 10²³ atoms

No. of moles of Na = 1.99 moles

1.20 X 10²⁴ atoms of Na contains 1.99 moles of Na

Now for mass,

No. of Moles Na = mass of Na/ Molecular mass of Na

Molecular mass of Na  = 23 g/ mol

Mass of Na = 23 g/ mol X 1.99 mol

Mass of Na = 45.77 grams

Hope it helps U !!

Answer 2

$\checkmark$ Given:

1.20 × 10²⁴ atoms of Sodium

$\checkmark$ To Find:

Mass of 1.20 × 10²⁴ atoms of Sodium

$\checkmark$ Solution:

We know that,

1 mole of any substance contains 6.022 x 10²³ atoms

Given that,

1.20 × 10²⁴ atoms of Sodium

Mathematically,

$\sf 1 \ mole \longrightarrow 6.022 \times 10^{23} \ atoms$

Therefore,

$\sf "x" \ moles \longrightarrow 1.20 \times 10^{24} \ atoms$

By cross-multiplication,

We get,

$\sf \implies x=\dfrac{1 \times 1.20 \times 10^{24}}{6.022 \times 10^{23}} \ moles$

On further simplification,

We get,

$\green{\sf \implies x=1.99 \ moles}$

Hence,

1.20 × 10²⁴ atoms of Sodium contains 1.99 moles of Sodium

We know that,

Mass of Sodium = 23 u

Hence,

1 mole of Sodium has mass of 23 g

We know that,

$\red{\bigstar \ \boxed{\sf n=\dfrac{m}{M}}}$

Here,

• n = Number of moles

• m = mass of Sodium

• M = Molecular mass of Sodium

According to the Question,

We are asked to find the mass of 1.20 × 10²⁴ atoms of Sodium

So, we must find Mass of Sodium (m)

Hence,

$\implies \sf m=n \times M$

We found out that,

• n = 1.99 moles

We know that,

• M = 23 g

Substituting the values,

We get,

$\sf \implies m=1.99 \times 23 \ grams$

$\pink{\sf \implies m=45.77 \ grams}$

Therefore,

Mass of 1.20 × 10²⁴ atoms of Sodium is 45.77 grams