# Water has a mass per mole of 18.0 g/mol, and each water molecule (H2O) has 10 electrons.?

A. How many electrons are there in 3 liters of water? (A liter is 1.00 multiplied by 10-3 m3)?

B. What is the net charge of all these electrons?

• This is just unit conversion, made confusing for you.

3 liters

x 10-3 m3/L

x 10^6 cm3/m3

x 1.00 g/cm3 = 3,000g

3,000g x 1 mol/18g x Na molecules/mole x 10 electrons/molecule = your answer

• to transform from molecules to mass, you could desire to maintain on with this conversion course: molecules—>moles—->grams Divide the molecules via 6.022 x 10^23 (Avogadro’s huge style) to discover the style of moles. => 3.55 x 10^22 / 6.022 x 10^23 = .590 (3 important digits) x 10^-a million = .05895… mol H20 Now convert the moles to grams via multiplying the moles via the molar mass of water (H is extra or less a million g/mol, O is extra or less sixteen g/mol) = .05895… H20 x ((a million g/mol H x 2) + (sixteen g/mol O)) = .05895.. mol H20 x (17 g/mol H20) = a million.00 g H20 (alter using important digits) =D

• 1st work out how many moles in 3l of water, but

we need to know the density of water for that.

………..

net charge =10 * total no of electrons * charge on an electron