Explanation:
15 8 O ---> 15 7 N + 0 1 e
Element: Oxygen
Mass Number: 16 u
Decay: Beta
238 92 U ----> 234 90 Th + -4 -2 e
Element: Uranium
Mass Number: 238.051 u
Decay: Alpha
Answer:
From the following enthalpy of reaction data and data in Appendix C, calculate ΔH∘f for CaC2(s): CaC2(s)+2H2O(l)→Ca(OH)2(s)+C2H2(g)ΔH∘=−127.2kJ
ΔHf°(C2H2) = 227.4 kJ/mol
ΔHf°(H2O) = -285.8 kJ/mol and
ΔHf°(Ca(OH)2) = -985.2 kJ/mol
(Ans)
ΔHf° of CaC2 = -59.0 kJ/mol
Explanation:
CaC2(s) + 2 H2O(l) → Ca(OH)2(s) + C2H2 (g) = −127.2kJ
ΔHrxn = −127.2kJ
ΔHrxn = ΔHf°(C2H2) + ΔHf°(Ca(OH)2) - ΔHf°(CaC2)- 2ΔHf°(H2O);
ΔHf°(CaC2) = ΔHf°(C2H2) + ΔHf°(Ca(OH)2) - 2ΔHf°(H2O) – ΔHrxn
Where
ΔHf°(C2H2) = 227.4 kJ/mol
ΔHf°(H2O) = -285.8 kJ/mol and
ΔHf°(Ca(OH)2) = -985.2 kJ/mol
ΔHf°(CaC2) =227.4 - 985.2 + 2x285.8 + 127.2 = -59.0 kJ/mol
ΔHf°(CaC2) = -59.0 kJ/mol
Answer:
About 7.886 grams
Explanation:
8 sulfurs will have a molar mass of 32.065*8=256.52g, while 32 flourines will have a molar mass of 18.998*32=607.936. In total, this is a molar mass of 864.456.
2.34/256.52 * 864.456=7.886g
Hope this helps!
<span>In a titration, the substance that is unknown and being identified is called analyte. A titration is where a known solution or concentration called the titrant is used to identify and measure an unknown substance which is the analyte.</span>
A calorimeter contains 500 g of water at 25°C.....
the temperature of the water inside the calorimeter is 39.4°C.....
The specific heat of water is 4.18 J/g-°C.
energy needed to heat the water = specific heat * mass * temp difference
= 4.18 J/g-°C * 500 g * (39.4°C - 25°C)
= 4.18*500*14.4
= 30096J
or approx. 30kJ