Question

how many molecules of h2o are equivalent to 97.2 grams of h2o

Answer 1

Answer:

3.25×10²⁴ molecules

Explanation:

From the question given above, the following data were obtained:

Mass of H₂O = 97.2 g

Number of molecule of H₂O =?

From Avogadro’s hypothesis, we understood that:

1 mole of H₂O = 6.02×10²³ molecules

Next, we shall determine the mass of 1 mole of H₂O. This can be obtained as follow:

1 mole of H₂O = (2×1) + 16

= 2 + 16

= 18 g

Thus,

18 g of H₂O = 6.02×10²³ molecules

Finally, we shall determine the number of molecules in 97.2 g of H₂O. This can be obtained as follow:

18 g of H₂O = 6.02×10²³ molecules

Therefore,

97.2 g of H₂O = 97.2 × 6.02×10²³ / 18

97.2 g of H₂O = 3.25×10²⁴ molecules

Thus, 97.2 g of H₂O contains 3.25×10²⁴ molecules.

Answer 2

Answer:

5.4 moles of H2O are equivalent to 97.2 grams.

3.25 x 10^24 molecules of H2O equivalent to 97.2 grams.

Explanation:

Gram molecular mass of H2O =  1 + 1 + 16 = 18g

We use unitary method.

1 mole of H2O = 18g

? moles of H2O = 97.2g

= 97.2/18 = 5.4 moles

Now as 1 mole = 6.023 x 10^23  molecules

we can say that 5.4 moles = 5.4 x 6.023 x 10^23 molecules

                                            = 3.25 x 10^24 molecules of H2O