Answer:
554.86kj
Explanation: Since 1 mole of CaC2=15.14kj yield 1mole of C2H2
The enthalpy change of H2O is 2*285=570
570+-15.14=554.86kj
Hence Hp is 554.86kj
He=Hp
Answer: 9.9 grams
Explanation:
To calculate the moles, we use the equation:
a) moles of 
b) moles of 
According to stoichiometry :
1 mole of combine with 1 mole of
Thus 0.33 mole of will combine with =
mole of
Thus is the limiting reagent as it limits the formation of product.
As 1 mole of give = 1 mole of 
Thus 0.33 moles of give =
of
Mass of 
Thus theoretical yield (g) of produced by the reaction is 9.9 grams
Answer:
D. Ni²⁺
Explanation:
We know at once that the answer cannot be A or C, because Ni and Cu are already in their lowest oxidation states.
The correct answer must be either B or D.
An electrolytic cell is the opposite of a galvanic cell. In the former, the reaction proceeds spontaneously. In the latter, you must force the reaction to occur.
One strategy to solve this problem is:
- Look up the standard reduction potentials for the half reaction·
- Figure out the spontaneous direction.
- Write the equation in the reverse direction.
1. Standard reduction potentials
E°/V
Cu²⁺ + 2e⁻ ⟶ Cu; 0.3419
Ni²⁺ + 2e⁻ ⟶ Ni; -0.257
2. Galvanic Cell
We reverse the direction of the more negative half cell and add.
<u>E°/V
</u>
Ni ⟶ Ni²⁺ + 2e⁻; 0.257
<u>Cu²⁺ + 2e⁻ ⟶ Cu; </u> 0.3419
Ni + Cu²⁺ ⟶ Cu + Ni²⁺; 0.599
This is the spontaneous direction.
Cu²⁺ is reduced to Cu.
3. Electrochemical cell
<u>E°/V</u>
Ni²⁺ + 2e⁻ ⟶ Ni; -0.257
<u>Cu ⟶ Cu²⁺ + 2e⁻; </u> <u>-0.3419</u>
Cu + Ni²⁺ ⟶ Ni + Cu²⁺; -0.599
This is the non-spontaneous direction.
Ni²⁺ is reduced to Ni in the electrolytic cell.
Taurine (C2H7NO3S) is another chemical found in energy drinks,and sports drinks but primarily the energy drink Red bull.Sports Drinks. Balanced mixture of sugar, salt, and other additives keeps athletes going strong.
Answer: option A. Cobalt
Explanation:
1) Data:
Q = 1.24 × 10⁶ J
m = 2 kg
Tf = 1768 K
Ti = 298 K
Cs = ?
2) Formula:
Q = m Cs ΔT
ΔT = Tf - Ti = 1,768K - 298K = 1,470K
3) Calculations:
i) Solve for Cs:
Cs = Q / [ m ΔT]
ii) Substitute the data:
Cs = 1.24 × 10⁵ J / [ 2kg (1768K - 298K) ] = 421 J / (kg K)
4) Compare with the specific heats (Cs) of the vaious metals given and you find that it is Cobalt.
