<h3><u>Answer</u>;</h3>
pH =7.58
<h3><u>Explanation;</u></h3>
The KOH will react with the HClO to produce KClO. You will have a solution containing unreacted HClO and KOH. This is a buffer solution.
Equation:
HClO + KOH → KClO + H2O
HClO reacts with KOH in 1:1 molar ratio
Mol HClO in 50mL of 0.150M solution = 50/1000*0.150 = 0.0075 mol HClO
Mol KOH in 30mL of 0.150M solution = 30/1000*0.150 = 0.0045 mol KOH
These react to produce 0.0045 mol KClO and there is 0.0030 mol HClO unreacted
Volume of solution = 50mL + 30mL = 80mL = 0.080L
Molarity of HClO in solution = 0.0030/0.080 = 0.0375M
Molarity of KClO in solution = 0.0045/0.080 = 0.0562M
Using the Henderson-Hasselbalch equation we can calculate the pH;
pKa HClO = -log ( 4.0*10^-8) = 7.40
pH = pKa + log ([KClO]/[HClO])
pH = 7.40 + log( 0.0562/0.0375)
pH = 7.40 + log 1.50
pH = 7.40+ 0.18
pH = 7.58
From the balanced chemical reaction, we can see that for
every 4 moles of Fe (iron) formed, the heat released or heat of reaction is
1.65 x 10^3 kJ.
So calculate the moles of iron first:
moles iron = 250 g / (55.85 g/mol) = 4.48 mol
So the heat of reaction is:
δhrxn = (-1.65 x 10^3 kJ / 4 mol) * (4.48 mol) = -1.85 kJ
The easiest answer and most relevant is because it didn't sink
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Answer:
1.) The aluminum block
2.) more than the nail it came from
3.) Rust contains iron and oxygen
Explanation:
1.)
Mass, Density, and Volume are related by the following equation;
Mass = Volume*Density
Solving for volume;
Volume = Mass/Density
If Mass is constant then;
Volume ∝ 1/Density ; That is volume and density will be inversely proportional. The larger the volume the smaller the density
2.)
If an iron nail were allowed to rust completely, you should find that the rust weighs more than the nail it came from since Iron combines with oxygen and water from the air to form rust.
3.)
Rust contains iron and oxygen.
Rust is composed or made up of hydrated iron(III) oxides Fe2O.
