Question

Commercially available solution of SPT has a density of 3.10 g/mL. Water (1.00 g/mL) can be added to the original SPT solution, to produce a desired density. What percent of the SPT solution must consist of WATER to give an overall density of 2.75 g/mL?

Answer 1

The reciprocal of the density, ρ, of a mixture is equal to the sum of the reciprocal of the densities of the constituents multiplied by their respective proportions ($x_i$) in the solution, $\displaystyle \dfrac{1}{\rho_{(mixture)}} = \sum \dfrac{x_i}{\rho _i}$

The percentage of water in the 2.75 g/mL SPT solution is $\underline{16. \bar6 \ \%}$

Reason:

Known parameter:

Density of SPT = 3.10 g/mL

Density of water = 1.00 g/mL

Required:

The percentage of water in 2.75 g/mL SPT solution

Solution:

Let x the volume of water added per 100 mL of 2.75 g/mL SPT solution, we have;

Mass of water in the solution = x mL × 1.00 g/mL = x g

Mass of commercial SPT = (100 - x) mL × 3.10 g/mL = (310 - 3.1·x) g

$Density = \dfrac{Mass}{Volume}$

The density of the 2.75 g/mL SPT solution is given as follows;

$Density \ of \ 100\ mL, \ 2.75 \ g/mL = \dfrac{(310 - 3.1\cdot x + x) \ g}{100 \ mL}$

100 mL × 2.75 g/mL =( 310 - 2.1·x) g

310 - 275 = 2.1·x

$x = \dfrac{310 - 275}{2.1} = \dfrac{50}{3} = 16.\overline 6$

Given that the reference quantity of the proportion of water in the solution is 100 mL of the 2.75 g/mL SPT solution, the percentage (per 100) of water in the overall solution is the value of x

Therefore;

• The percent of the SPT solution that must consist of water to give  an overall density of 2.75 g/mL is x = $\displaystyle {\underline {16.\overline 6 \ \%} }$

Learn more here: brainly.com/question/13346179