Question

A scientist is working with two different concentrations of hydrochloric acid (HCl) . One bottle is 70% HCl, and the other is 30% HClFor their experiment they need 1 liter of 40% HCI How many liters of the 70% solution do they need ? [ Select ] How many liters of the 30% solution? [ Select

Answer 1

Answer:

They need 0.75 liters of the 30% solution

Step-by-step explanation:

Let the number of liters of 70% needed be x while the number of 30% needed be y

Since they need a total of 1 liter 40%

Hence;

x + y = 1 •••••••(i)

Furthermore;

70% * x + 30% * y = 1 * 40%

0.7x + 0.3y = 0.4 ••••••(ii)

From equation i, x = 1-y

insert this into equation ii

0.7(1-y) + 0.3y = 0.4

0.7 -0.7y + 0.3y = 0.4

0.7 -0.4 = 0.7y -0.3y

0.4y = 0.3

y = 0.3/0.4

y = 0.75 liters