Help pls!! Question number 7

6.69×10²⁵ molecules

Explanation:

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

Mass per bottle of water = 500 g

Number of molecules of water =?

Next, we shall determine the mass of 4 bottles of water. This can be obtained as follow:

1 bottle = 500 g of water

Therefore,

4 bottles = 4 × 500

4 bottles = 2000 g of water.

Finally, we shall determine the number of molecules of in 2000 g of water. This can be obtained as follow:

From Avogadro's hypothesis:

1 mole = 6.02×10²³ molecules.

1 mole of water (H₂O) = (2×1) + 16

= 2 + 16

= 18 g

Thus, we can say that:

18 g of water = 6.02×10²³ molecules.

Therefore,

2000 g = 2000 × 6.02×10²³ / 18

2000 g = 6.69×10²⁵ molecules

From the calculations made above, we can conclude that the chemist consumes 6.69×10²⁵ molecules of water daily.

yes the answer is total mass in unchanged   : )