Question

The molecular mass of Methane (CH4) is 16

(a) What is the mass of 1 GMM of CH4?

(b) Calculate the number of mole molecules in 160 g of CH4 ?

(c) What is the mass of 5x 6.022x1023 CH4 molecules?​

Answer 1

Answer:

B is the correct answer

Answer 2

Answer:

a) The mass of 1 GMM of CH₄ is 16 g/mol.

b) The number of moles in 160g of CH₄, is 10 mol.

  The number of molecules in 160 g of CH₄ is 6.022 × 10²⁴ molecules.

c) The mass of  5 x 6.022 x 10²³ CH₄ molecules is 80g.

Explanation:

Given,

The molecular mass of methane, CH₄ = 16g/mol

a)  Mass of 1 GMM of CH₄ =?

• GMM is known as the gram molecular mass.
• It is the mass of 1 mole of the molecule.

Basically,

GMM = Molar mass

Therefore,

Mass of 1 GMM of CH₄ = 16 g/mol.

b) Number of moles in 160g of CH₄, n=?

   The number of molecules in 160 g of CH₄ =?

• Molar mass of CH₄, M = 16 g/mol
• Mass of CH₄, m = 160 g

As we know,

• $n = \frac{m}{M}$ = $\frac{160}{16}$ = 10 mole

Now, 1 mole = 6.022 × 10²³ molecules

So,   10 mole = 10 × 6.022 × 10²³ molecules = 6.022 × 10²⁴ molecules.

Hence,

Number of moles in 160g of CH₄, n= 10 mol

The number of molecules in 160 g of CH₄ = 6.022 × 10²⁴ molecules.

c) Mass of  5x 6.022 x 10²³ CH₄ molecules=?

As we know,

• 1 mole = 6.022 x 10²³ molecules
• $1 molecule = \frac{1}{6.022 \times 10^{23}} mole$
• $5\times 6.022 \times10^{23} molecules = \frac{5\times 6.022 \times10^{23} }{6.022 \times10^{23}} moles$ = 5 moles

Now,

From the equation of the number of moles we can calculate the mass of molecules:

• $n = \frac{m}{M}$

Here,

• n = number of moles = 5 moles
• M = Molar mass of CH₄= 16 g/mol
• m = mass of 5x 6.022 x 10²³ CH₄

So,

• $5 = \frac{m}{16}$
• m = 80 g

Hence, mass of  5x 6.022 x 10²³ CH₄ molecules = 80g