Question

How many milliliters of concentrated hydrochloric acid solution (36.0% HCl by mass, density = 1.18 g/mL) are required to produce 10.0 L of a solution that has a pH of 2.22?

Answer 1

Data given is 36% Hd by mass dentity = +18 gimb pH = 2.22 {equired volume = 10.0L of Hd Solution solution - We know that pH is defined as Negative logarithm of hydrogen ion concentration, we can calculate the concentration of hydrogen in vring pH= 2:22 value. 2122= -log.. [4*] TH+] = 10227 = 0.0060256 more! Since Hydrochloric acid is strong acid the concentration of acid will be equal to concentration of Hydrogen in cỏ [H] = 0-0 0 6 056 m2 L- 1. To prepare 10.0L of Hydrochloric acid solution we need to find the number of moles of Hel mole - concentration X Volume (n= cv) moles of Hd = 0.0060256 molly X 10L MCHUJ = 0.060256 mol Now we can calculate mass of pure HU (ie 100% Hal by mas mass of Hd = moles of Hel x Molar mass of Hl 1 = 0.060256 molx 36.461 gmott = 2-197 g

- since we are provided with only 36% Hel by mass we need to calculate mass of Hel, as shown below) - mass of pure Hel 0:36 364-1=0036 mass = 100 2.197 g m = 0.36 - 6.103 g - since density of 36% Hel by mass is given we can now calculate volume of the same va mass ing density gomel V V= 6.103 g - 118 gome) a = 5.172 mL So As we explained above we need 5.172 mL of 264 Hel by mass to make 1000L of He solution with pH = 2022