Question

PHYSICS

Answer 1

Answer:

c) 8.3 x 10^24 molecules

Explanation:

First of all, we convert the volume of the glass of water from mL to $cm^3$:

$V=250 mL = 250 cm^3$

The relationship between mass and volume is:

$d=\frac{M}{V}$

where

$d=1.00 g/cm^3$ is the density of water

M is the total mass of the glass of water

$V=250 cm^3$ is the volume of the water in the glass

Solving for M,

$M=dV=(1.00)(250)=250 g = 0.250 kg$

Now we know that the mass of a single molecule of water is

$m=3.0\cdot 10^{-26}kg$

The total mass of the water in the glass can be written as

$M=Nm$

where

N is the number of molecules in the glass of water

Solving for N, we find:

$N=\frac{M}{m}=\frac{0.250}{3.0\cdot 10^{-26}}=8.3\cdot 10^{24}$