Asample of grape juice has a hydroxide ion concentration of 1.4 × 10-10 m

what is the concentration of hydronium ion?

__x 10 x^-5 m

The relation between hydroxide ion (OH-) and hydronium ion (H3O+) is given by:

pH + pOH = 14, which is equivalent to [H3O+] [OH-] = 10^ -14

=> [H3O+] = (10^ -14) / [OH-] = (10^ -14) / (1.4*10^-10) = 0.71 * 10^ - 4 = 0.071 * 10^-5

0.071 * 10 ^ -5
 

Molarity when 30g is dissolved in 100g of water = 0.5128moles/ dm^3
Molarity when 15g is dissolved in 100g of water= 0.2564moles/dm^3

Therefore the statement is not right, as the 15g has exactly half the molarity as the 30 g one. molarity only changes if the volume changes or the mass of the salt changes, it's given by the equation "number of moles X volume"