the number of electrons present in 18 ml of water at 4 degrees celsius?
a)6.023*10^24
b)6.023*10^23
c)4.76*10^21
d)4.76*10^20
If you assume the density of H2O is 1 g/mL, then 18 mL has a mass of 18 grams.
mols H2O = grams/molar mass = ?
There are 6.022E23 molecules in 1 mol.
There are 10 electrons in 1 molecule of H2O.
BTW, Avogadro's number is 6.022E23 and not 6.023E23.
To determine the number of electrons present in 18 ml of water at 4 degrees Celsius, we need to use the relationship between the number of particles, the amount of substance, and Avogadro's number.
The first step is to calculate the number of moles of water using the given volume. We can use the formula:
moles = volume (in liters) / molar volume
The molar volume of any ideal gas is approximately 22.4 liters at standard temperature and pressure (STP). However, water is not an ideal gas, but we can still use an approximation for our calculation.
So, let's convert the given volume from milliliters to liters:
18 ml = 18/1000 L = 0.018 L
Next, we can calculate the number of moles of water:
moles = 0.018 L / 22.4 L/mol (approximate molar volume at STP)
moles ≈ 0.000803 moles
Now that we have the number of moles of water, we can relate it to the number of electrons using Avogadro's number. Avogadro's number states that there are approximately 6.023 × 10^23 particles (atoms, ions, or molecules) in one mole of a substance.
So, the number of electrons can be calculated as:
number of electrons = moles x Avogadro's number
Let's substitute the values:
number of electrons = 0.000803 moles x 6.023 × 10^23 particles/mole
number of electrons ≈ 4.833 × 10^20 electrons
So, the answer is approximately 4.76 × 10^20 electrons, which corresponds to option (d).