Question

Positive and negative charge in 18 cc of water is (1) 9 = 9.63 x 105 C (2) 9 = + 1.63 x 105 C (3) q= 9.63 x 10-5C (4) g = +2.63 x 10-5C​

Answer 1

Answer:

Amount of water = 18 cc = 18 mL [ 1cc = 1mL ]

we know, density of water = 1 g/mL

so, mass of given amount of water = density × volume = 18 mL × 1 g/mL = 18g

we also know, Molecular weight of water , H₂O = 18g/mol

so, number of moles of water = weight/Molecular weight = 18/18 = 1 mol

In water , H₂O there are 10 electrons [ 2 of Hydrogen atoms and 8 of oxygen atom ]

so, number of moles of electrons in 1 mole of water = 10 × 1 = 10

now, number of electrons = number of moles × avogadro's number

= 10 × 6.023 × 10²³ = 6.023 × 10²⁴

We know, charge on an electron = 1.6 × 10⁻¹⁹ C

so, charge on 6.023 × 10²⁴ electrons = 6.023 × 10²⁴ × 1.6 × 10⁻¹⁹ C

= 9.632 × 10⁵ C

Because you know water is a neutral molecule, it means positive charge and negative charge will be the same amount.

Hence, positive charge = 9.632 × 10⁵C

negative charge = -9.632 × 10⁵C