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>
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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>
The reaction CO₂(g) → C(s) +O₂(g) is a decomposition reaction is true
Explanation
A Decomposition reaction is a reaction in which involve breaking down a compound into two or more simpler substances.
The reaction above is a decomposition reaction since CO₂ molecule is broken down into C (an element) and O₂ (a molecule).
When the object has something added to it
Answer: properties
Explanation:
The element which has the properties
Mallablity
Ductility
Lusterous
High electric. Conductivity
High tensile strength is said to be metal.
