Answer:
The enthalpy of the second intermediate equation is altered by halving its value and changing the sign.
Explanation:
Let's examine both the first and second intermediate reactions alongside the overall equation concerning the examined process;
First reaction;
Ca (s) + CO₂ (g) + ½O₂ (g) → CaCO₃ (s) ΔH₁ = -812.8 kJ
Second reaction;
2Ca (s) + O₂ (g) → 2CaO (s) ΔH₂ = -1269 kJ
Thus, the overall reaction becomes;
CaO (s) + CO₂ (g) → CaCO₃ (s) ΔH =?
According to Hess's law, which states that the total heat change in a reaction is equal to the sum of the heat changes for each step, we cannot simply sum the enthalpies for this overall reaction. Instead, we obtain the overall enthalpy by halving the second intermediate reaction's enthalpy and changing its sign before adding, as illustrated below;
Enthalpy of Intermediate reaction 1 + ½(-Enthalpy of Intermediate reaction 2) = Enthalpy of Overall reaction
As the ball descends down the hill, its potential energy diminishes while its kinetic energy rises.
The ball's potential energy will decrease as it moves down the slope, and its kinetic energy will experience an increase.
Kinetic energy refers to the energy possessed by an object in motion.
K. E = 
m v²
where m is the mass of the ball
and v represents the ball's velocity.
Potential energy is the energy associated with an object's position as it traverses down a slope, expressed as:
P.E = mgh
with m as the mass of the ball,
g as gravitational acceleration, and h as the height.
It is clear that as the object descends, its height decreases, while its velocity increases.
learn more:
Potential energy
Solution:
Molality measures the concentration of a solute in a solution, defined by the amount of solute per specific mass of solvent.
Thus,
Molality = moles of solute / kg of solvent.
Therefore, kg of solvent = moles of solute / molality.
moles of solute = mass / molar mass
= 25.31 g / 101.1 g/mole
= 0.2503 mole.
kg of solvent = 0.2503 mole / 0.1982 m
= 1.263 kg
= 1263 g.
This is the final answer.
<span>(NH4)2CO3 -> 96.09 g/mol
(6.995g ammonium carbonate)(1mol ammonium carbonate/ 96.09 g ammonium carbonate) = 0.072796 mol ammonium carbonate
In this calculation, the unit 'grams' cancels out as it's present in both the numerator and the denominator, leading to 'mol' being the remaining unit.
Examining the formula (NH4)2CO3, it can be interpreted as:
2 mol (NH4) + 1 mol (CO3) = 1 mol (NH4)2CO3
This means every mole of ammonium carbonate yields one mole of carbonate ions and two moles of ammonium ions.
(0.072796 mol ammonium carbonate) = (0.072796 mol carbonate ion) + (0.363981 mol ammonium ion) </span>
For KNO₃, the mass is 346g. The molar mass can be computed as (39.098) + (14) + (15.99*3), which results in 101.068 gmol⁻¹. The volume of the solution is given as 750ml, equivalent to 0.75dm³. The formula for molarity is (mass of solute/molar mass of solute)*(1/volume of solution in dm³). Accordingly, molarity = (346/101.068)*(1/0.75), yielding 4.56 mol dm⁻³.
