Question

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The density of water at 4.00°C is 0.967 g/mL. How many molecules of water are present in a 499.8 mL bottle of water? Express your answer to the correct number of significant figures. Be sure to show all steps completed to arrive at the answer.

Answer 1

density of water at 4.00c is 0.967 g/mL. Volume of water=499.8mL

Mass of water=density x volume= 0.967 x 499.8=483.3066g

Number of moles of water molecules in given of water = givenmass/molarmass=483.3066/18=26.85

we know that 1 mole has 6.022 x 1023 molecules of water

so the number of water=6.022 x 1023 x 26.85=161.69 x 1023 =1.62 x 1025 molecules of water is its upto 3 significant figure.

Step-by-step explanation:

Answer 2

161.69×10²³ molecules

Step-by-step explanation:

Given data:

Volume of water = 499.8 mL

Density of water = 0.967 g/mL

Number of molecules of water = ?

Solution:

First of all we will calculate the mass of water.

Density = mass/volume

0.967 g/mL = mass/499.8 mL

Mass = 0.967 g/mL × 499.8 mL

Mass = 483.3 g

Number of moles of water:

Number of moles = mass/molar mass

Number of moles = 483.30 g / 18 g/mol

Number of moles = 26.85 mol

1 mole contain 6.022×10²³ molecules

26.85 mol ×6.022×10²³ molecules / 1mol

161.69×10²³ molecules