A saline solution contains 1.1% NaCl by mass. How much NaCl is present in 87.2 g of this solution?
To find the amount of NaCl present in 87.2 g of the solution, we can use the concentration of NaCl in the solution, which is 1.1% by mass.
First, we need to determine the mass of NaCl in the solution. We do this by multiplying the total mass of the solution (87.2 g) by the concentration of NaCl (1.1%).
Mass of NaCl = 87.2 g x 1.1% = 87.2 g x 0.011
To calculate this, we multiply 87.2 g by 0.011.
A 5.00-ml sample of a H3PO4 solution of unknown concentration is titrated with a 0.1003 M NaOH solution. A volume of 6 .55ml of the Na OH solution was required to reach the endpoint. What is the concentration of the unknown H3PO4 solution?
This is not the answer but it the same thing:
1.3 g / 100 g = 0.013.
0.013 * 89.2 g = 1.1596 g
= 1.16 g.
Or, another way.
1.1% w/w means 1.1g NaCl in 100 g solution.
You want to know how much is there in 87.2 g (and not 100g); therefore,
1.1 x (87.2/100) = ?