Final answer:
To find the mass of 9.4x10^25 molecules of H2, convert the number of molecules to moles using Avogadro's number and then multiply by the molar mass of H2. The result is approximately 312285.7142 grams.
Step-by-step explanation:
To calculate the mass of 9.4x1025 molecules of H2, we first need to find out how many moles this number of molecules represents. Using Avogadro's number, which is 6.02 x 1023 molecules per mole, we can perform this conversion.
The number of moles (n) is calculated using the formula:
n = Number of molecules ÷ Avogadro's number
n = 9.4x1025 molecules ÷ 6.02 x 1023 molecules/mol
n = 156142.8571 moles
Now that we have the moles of H2, we can calculate the mass. The molar mass of H2 (which consists of two hydrogen atoms) is approximately 2 grams per mole. We calculate mass (m) using the formula:
m = n × molar mass
m = 156142.8571 moles × 2 grams/mole
m = 312285.7142 grams
Therefore, 9.4x1025 molecules of H2 have a mass of approximately 312285.7142 grams.