Question

9) Какую массу имеют 8*10^22 молекул воды?

Answer 1

Масса m=NM/Na ( Na =6*10²³ 1/моль  -число Авогадро)
М(Н₂О) =1*2 +16 =18 г/моль =0,018 кг/моль
m=8*10²² *0,018/6*10²³ =0,0024 кг =2,4 г

Answer 2

Calculating the Mass of 8*10^22 Water Molecules

To calculate the mass of 8*10^22 water molecules, we can use the following steps:

1. Molar Mass of Water: The molar mass of water (H2O) is approximately 18.01528 grams per mole.

2. Number of Molecules: Given the number of molecules (8*10^22), we can use Avogadro's number to convert this to moles.

3. Calculation: We can use the formula: \[ \text{Mass} = \text{Number of moles} \times \text{Molar mass} \]

Substituting the values, we get: \[ \text{Mass} = \left( \frac{8*10^{22}}{6.022*10^{23}} \right) \times 18.01528 \]

Let's calculate the mass using the given information.

Calculation

Using the given information and the molar mass of water, we can calculate the mass of 8*10^22 water molecules.

\[ \text{Mass} = \left( \frac{8*10^{22}}{6.022*10^{23}} \right) \times 18.01528 \]

\[ \text{Mass} \approx 2.39 \, \text{grams} \]

So, the mass of 8*10^22 water molecules is approximately 2.39 grams.

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