Question

1) the mass of an atom of oxygen is 16.0 u. express it in kg
2) the mass of a molecule of hydrogen is 3.332 ×10^-27 find the mass of 1 kg mol of hydrogen gas​

Answer 1

Answer:

• 1. The mass of an atom of oxygen in kg is $2.656 \times 10^{-26}$

• 2. The mass of 1 kg mol if hydrogen gas is 2.0 kg.

Explanation:

$\underline{\pink{\tt{1) The \: mass \: of \: one \: atom \: of \: the \: element \: oxygen \: :}}}$

Given:

Mass of one atom of the element oxygen = 16.0 u (or a.m.u)

1 u (or a.m.u) is $\frac{1}{2}th$ the mass of one carbon-12 atom.

The mass of $6.02 \times 10^{23}$ atoms if carbon - 12 is 12 kg.

So,

1 u (or a.m.u) = $\frac{1}{2} \times \frac{12}{6.02 \times 10^{26}}kg$

= $1.66 \times 10^{-27} kg$

Therefore,

1 u (or a.m.u) = $1.66 \times 10^{-27} kg$

Solution:

Now,

The mass of one atom of oxygen

= $16.0 \times 1.66 \times 10^{-27} kg$

= $2.656 \times 10^{-26} kg$

Therefore, the mass of one atom of the element oxygen is $</u></em></strong><strong><em><u>\</u></em></strong><strong><em><u>underline{</u></em></strong><strong><em><u>2.656 \times 10^{-26} kg</u></em></strong><strong><em><u>}</u></em></strong><strong><em><u>$

$\underline{\pink{\tt{2) The \: mass \: of \: 1kg \: mol \: of \: hydrogen \: gas \: :}}}$

Given:

The Mass of one molecule of hydrogen = $3.332 \times 10^{-27}kg$

Solution:

1 kg mol of the hydrogen gas will contain$6.02 \times 10^{26}$ molecules of hydrogen

So,

The mass of 1 kg mol if hydrogen gas = $( 6.02 \times 10^{26} ) \times 3.332 \times 10^{-27}kg$

= 2.0 kg

Therefore, the mass of 1 kg mol of hydrogen gas is 2.0 kg.