Question

no. of oxygen molecules present in 320 u of oxygen gas is ...?​

Answer 1

Moles = given mass/molar mass = 320/32 = 10 moles.

Now,

1 mole corresponds to Avogadro's number.

So, 10 moles corresponds to 10 times the Avogadro's number

= 6.022×10²⁴ molecules.

Answer 2

The number of oxygen molecules is 6.02×10²⁴ molecules.

Given - Mass

Find - Number of oxygen molecules

Solution - The number of oxygen molecules can be calculated using number of moles. So firstly calculating the number of moles.

Number of moles will be calculated by the formula -

Number of moles = mass ÷ molar mass

As per the known fact, the molar mass of oxygen molecules is 32 grams

Keep the values in formula to find number of moles

Number of moles = 320÷32

Number of moles = 10

As per the known fact, 1 mole of any substance contains Avogadro's number of molecules, which is 6.02×10²³

So, 10 moles will contain number of molecules = 6.02×10²³×10

Number of molecules = 6.02×10²⁴ molecules

Hence, the number of molecules in 320 u of oxygen gas is 6.02×10²⁴ molecules.

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