Answer:
b. 50ppm of Pb
c. 2x10⁻⁴M
j. no
Explanation:
The diluted sample has a concentration of 0.5 ppm of Pb. The sample was diluted from 1mL to 100mL. That means the dilution factor is:
100mL / 1mL = 100
That means, the sample was diluted 100 times from its original concentration.
As diluted sample has a concentration of 0.5ppm, the undiluted sample has a concentration of
0.5ppm×100 = <em>50ppm of Pb</em>
1 ppm means 1x10⁻⁴ % by mass, 50 ppm are 50x10⁻⁴ % by mass
As molar mass of Pb is 207g/mol, molarity of 0.050g / L a(50 ppm) are:
0.050gₓ (1mol / 207g) / 1L = <em>2x10⁻⁴M</em>
<em></em>
Based on EPA regulation, the maximum concentration of Lead in drinking water must be 0.015ppm. That means this water <em>is not safe to drink</em>
One correct thging is that there are the same amount of positive and negative atoms
Answer:
I think the answer is two
