Explanation:
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Answer : Option B) Lead
Explanation : Lead is chemical element which damages<span> the central nervous system, cardiovascular system, reproductive system, hematological system, and kidneys with overexposure as compared to other elements in the given option.</span>
<span>The molecular mass of sodium oxide (Na2O) is A. 61.97894. The molecular mass of a molecule (Mr) is the sum of atomic masses of its atoms (Ar). The molecular mass of sodium oxide is: Mr(Na2O) = 2 * Ar (Na) + Ar(O). From the periodic table, Ar(Na) = 22.989769 and Ar(O) = 15.9994. The molecular mass of sodium oxide is: Mr(Na2O) = 2 * 22.989769 + 15.9994 = 45.979538 + 15.9994 = 61.97894.</span>
Answer:
Trial Number of moles
1 0.001249mol
2 0.001232mol
3 0.001187 mol
Explanation:
To calculate the <em>number of moles of tritant</em> you need its<em> molarity</em>.
Since the<em> molarity</em> is not reported, I will use 0.1000M (four significant figures), which is used in other similar problems.
<em>Molarity</em> is the concentration of the solution in number of moles of solute per liter of solution.
In this case the solute is <em>NaOH</em>.
The formula is:

Solve for the <em>number of moles:</em>

Then, using the molarity of 0.1000M and the volumes for each trial you can calculate the number of moles of tritant.
Trial mL liters Number of moles
1 12.49 0.01249 0.01249liters × 0.1000M = 0.001249mol
2 12.32 0.01232 0.01232liters × 0.1000M = 0.001232mol
3 11.87 0.01187 0.01187liters × 0.1000M = 0.001187 mol
balanced equation =
3Cu(OH)2 + 2H3PO4 → Cu3(PO4)2 + 6H2O