I think because its the only one to be liquid at normal temperatures.
<u>Answer:</u> The acceleration of the object is 2m/s^2. If net force increases, acceleration will also increase and if mass increases, the acceleration will decrease.
<u>Explanation:</u>
Force is defined as the product of object's mass and acceleration.
Mathematically,
F = ma ......(1)
or,
a = F/m .....(2)
where,
F = Force exerted on an object = 60N
m = mass of an object = 30kg
a = acceleration of the object = ?
Putting values in above equation, we get:
a = 60 kg.m/s^2/30 kg = 2m/s^2
The acceleration of the car is 2m/s^2.
From equation 2, it is visible that acceleration is directly proportional to force. This means that \if force increases, acceleration also increases.
And acceleration is inversely proportional to mass of the object. This means that if mass increases, the acceleration decreases.
Hence, if net force increases, acceleration will also increase and if mass increases, the acceleration will decrease.
Answer:
-177.9 kJ.
Explanation:
Use Hess's law. Ca(s) + CO2(g) + 1/2O2(g) → CaCO3(s) ΔH = -812.8 kJ 2Ca(s) + O2(g) → 2CaO(s) ΔH = -1269.8 kJ We need to get rid of the Ca and O2 in the equations, so we need to change the equations so that they're on both sides so they "cancel" out, similar to a system of equations. I changed the second equation. Ca(s) + CO2(g) + 1/2O2(g) → CaCO3(s) ΔH = -812.8 kJ 2CaO(s) → 2Ca(s) + O2(g) ΔH = +1269.8 kJ The sign changes in the second equation above since the reaction changed direction. Next, we need to multiply the first equation by two in order to get the coefficients of the Ca and O2 to match those in the second equation. We also multiply the enthalpy of the first equation by 2. 2Ca(s) + 2CO2(g) + O2(g) → 2CaCO3(s) ΔH = -1625.6 kJ 2CaO(s) → 2Ca(s) + O2(g) ΔH = +1269.8 kJ Now we add the two equations. The O2 and 2Ca "cancel" since they're on opposite sides of the arrow. Think of it more mathematically. We add the two enthalpies and get 2CaO(s) + 2CO2(g) → 2CaCO3(s) and ΔH = -355.8 kJ. Finally divide by two to get the given equation: CaO(s) + CO2(g) → CaCO3(s) and ΔH = -177.9 kJ.
