25.9 kJ/mol. (3 sig. fig. as in the heat capacity.)
<h3>Explanation</h3>
The process:
.
How many moles of this process?
Relative atomic mass from a modern periodic table:
- K: 39.098;
- N: 14.007;
- O: 15.999.
Molar mass of 
:
.
Number of moles of the process = Number of moles of dissolved:
.
What's the enthalpy change of this process?
for 
. By convention, the enthalpy change 
measures the energy change for each mole of a process.
.
The heat capacity is the least accurate number in these calculation. It comes with three significant figures. As a result, round the final result to three significant figures. However, make sure you keep at least one additional figure to minimize the risk of rounding errors during the calculation.
Answer : The number of moles in 369 grams of calcium hydroxide is, 4.98 moles
Explanation : Given,
Mass of calcium hydroxide = 369 g
Molar mass of calcium hydroxide = 74.093 g/mole
Formula used :
Now put all the given values in this formula, we get the moles of calcium hydroxide.
Therefore, the number of moles in 369 grams of calcium hydroxide is, 4.98 moles
Answer:
d. K<1 E∘cell is negative
Explanation:
Since E⁰ = negative , ΔG = -nFE⁰ = -nF -ve = +ve.
Also, ΔG = -RTlnK
K = exp(-RTΔG)
Since ΔG = +ve, -RTΔG = -ve
K = 1/exp(RTΔG) < 1.
So our answer is E⁰ cell is negative and K < 1
Answer:
Mass = 99.8 g
Explanation:
Given data:
Mass of potassium nitride = ?
Mass of nitrogen produced = 10.65 g
Solution:
Chemical equation:
2K₃N→ 6K + N₂
Moles of nitrogen:
Number of moles = mass/ molar mass
Number of moles = 10.65 g / 28 g/mol
Number of moles = 0.38 mol
Now we will compare the moles of nitrogen with potassium nitride.
N₂ ; K₃N
1 : 2
0.38 : 2×0.38 =0.76
Mass of potassium nitride:
Mass = molar mass × number of moles
Mass = 131.3 g/mol × 0.76 mol
Mass = 99.8 g
4.6to the twelth power plus ten or something like that it has been a while since I have done the scientific notation but where ever you put in the number of zeros. is twelve
