All combustion reactions release energy true or false
2 answers:
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Answer:
The specific heat of the sample unknown metal is approximately 0.45 J/g °C.
General Formulas and Concepts:
<u>Thermodynamics</u>
Specific Heat Formula:
- <em>m</em> is mass (g)
- <em>c</em> is specific heat capacity (J/g °C)
- Δ<em>T</em> is the change in temperature
Explanation:
<u>Step 1: Define</u>
<em>Identify variables.</em>
<em>m</em> = 112 g
Δ<em>T</em> = 20.0 °C
<em>q</em> = 1004 J
<u>Step 2: Solve for </u><u><em>c</em></u>
- Substitute in variables [Specific Heat Formula]:
- Simplify:
- Isolate <em>c</em>:
- Round [Sig Figs]:
∴ specific heat capacity <em>c</em> is equal to around 0.45 J/g °C.
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Topic: AP Chemistry
Unit: Thermodynamics
Answer:
The answer to your question is 0.269 g of Pb
Explanation:
Data
Lead solution = 0.000013 M
Volume = 100 L
mass = 0.269 g
atomic mass Pb = 207.2 g
Chemical reaction
2Pb(s) + O₂(aq) + 4H⁺(aq) → 2H₂O(l) + 2Pb₂⁺(aq)
Process
1.- Calculate the mass of Pb in solution
Formula
Molarity =
Solve for number of moles
Number of moles = Volume x Molarity
Substitution
Number of moles = 100 x 0.000013
Number of moles = 0.0013
2.- Calculate the mass of Pb formed.
207.2 g of Pb ----------------- 1 mol
x g ----------------- 0.0013 moles
x = (0.0013 x 207.2) / 1
x = 0.269 g of Pb