Question

How many grams of a stock solution that is 85.5 percent H2SO4 by mass would be needed to make 150 grams of a 45.0 percent by mass solution? Show all of the work needed to solve this problem.

Answer 1

(150 grams)(45/100)=(x)(85.5/100)
67.5=.855(x)
x=78.947368 grams of stock solution

Answer 2

Answer : The mass of stock solution needed, 78.94 grams

Solution :

Formula used :

`C_1m_1=C_2m_2`

where,

`C_1` = amount of stock solution needed = ?

`C_2` = amount of stock solution given = 150 g

`m_1` = mass percent of
`H_2SO_4` = 85.5 %

`m_2` = mass percent of solution = 45 %

Now put all the given values in the above relation, we get

`C_1* (85.5)/(100)=(150g)* (45)/(100)`

`C_1=78.94g`

Therefore, the mass of stock solution needed, 78.94 grams