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15 votes
How many molecules of water are in the 30 mL water sample

User CrazySynthax
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1 Answer

24 votes
24 votes

Answer:

Step-by-step explanation:

These numbers are all approximate. You will have to consult your text to get exact numbers.

density = mass (grams)/ volume(mL)

density of water = 1 gram / 1 mL

given volume = 30 mL

mass = ?

density = mass / volume

1 = mass / 30 mL

mass = 1 * 30 mL = 30 grams

1 mol of water = 18.02 grams (2 * 1.01 + 16)

x mol of water = 30 grams

18.02 * x = 1 * 30

x = 30/18.02

x = 1.66 mol

Note this is the answer to the question that asks how many mols are in 30 mL of water.

1 mol of anything is 6.02 * 10^23 parts

1.66 mol = x

1*x = 1.66 * 6.02*10^23

x = 1.0022 * 10^24 particles

Answer: there are 1.0022*10^24 molecules of water in 30 mL of water

User BioTronic
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