Lead is a toxic metal that affects the central nervous system. A Pb-contaminated water sample contains 0.0012 % Pb by mass. What
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Answer : We can produce 125.7 g of .
Explanation : The reaction will be
The molecular mass of is 64.1 g/mol
and molecular mass of is 34.1 g/mol
For every mole of we would need twice of
moles, so for every 3 moles of
we need 16 moles of
Now, we can calculate number of moles
2.61 X (3/16) = 0.49 moles
Here, the molecular mass of is 256.8 g
multiplying it with the number of 0.49 moles we get, 256.8 X 0.49 = 125.7 g of .
Hence, 125.7 g of will be produced.
Answer:
0.51M
Explanation:
Given parameters:
Initial volume of NaBr = 340mL
Initial molarity = 1.5M
Final volume = 1000mL
Unknown:
Final molarity = ?
Solution;
This is a dilution problem whereas the concentration of a compound changes from one to another.
In this kind of problem, we must establish that the number of moles still remains the same.
number of moles initially before diluting = number of moles after dilution
Number of moles = Molarity x volume
Let us find the number of moles;
Number of moles = initial volume x initial molarity
Convert mL to dm³;
1000mL = 1dm³
340mL gives = 0.34dm³
Number of moles = initial volume x initial molarity = 0.34 x 1.5 = 0.51moles
Now to find the new molarity/concentration;
Final molarity = =
= 0.51M
We can see a massive drop in molarity this is due to dilution of the initial concentration.