Answer:
Lead is a chemical element with the symbol Pb (from the Latin plumbum) and atomic number 82. It is a heavy metal that is denser than most common materials. Lead is soft and malleable, and also has a relatively low melting point.
Explanation:
Typically kinetic energy changes is passed through objects when it crashes
Answer:
a. 
b. 0.092 M
Explanation:
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In this case, since for this titration process we know the used volume of 0.75-M sodium hydroxide needed to neutralize 155 mL of the acid, we first need to write the undergoing chemical reaction between them:

This, since there is 1:2 mole ratio between the acid and the base, at the equivalent point we must respect:

That in terms of concentrations and volumes is:

Thus, the concentration of acid was:

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0.0340 g O2
<em>Step 1.</em> Write the balanced chemical equation
4Fe(OH)^(+) + 4OH^(-) + O2 + 2H2O → 4Fe(OH)3
<em>Step 2</em>. Calculate the moles of Fe^(2+)
Moles of Fe^(2+) = 50.0 mL Fe^(2+) × [0.0850 mmol Fe^(2+)/1 mL Fe^(2+)]
= 4.250 mmol Fe^(2+)
<em>Step 3</em>. Calculate the moles of O2
Moles of O2 = 4.250 mmol Fe^(2+) × [1 mmol O2/4 mmol Fe^(2+)]
= 1.062 mmol O2
<em>Step 4</em>. Calculate the mass of O2
Mass of O2 = 1.062 mmol O2 × (32.00 mg O2/1 mmol O2) = 34.0 mg O2
= 0.0340 g O2