Answer:
Endothermic reactions is the result of heat being absorbed.
Explanation:
Melting ice cubes. Melting solid salts. Evaporating liquid water. Converting frost to water vapor (melting, boiling, and evaporation, in general, are endothermic processes.
(These are all examples of endothermic reactions.)
Answer:
-800 kJ/mol
Explanation:
To solve the problem, we have to express the enthalpy of combustion (ΔHc) in kJ per mole (kJ/mol).
First, we have to calculate the moles of methane (CH₄) there are in 2.50 g of substance. For this, we divide the mass into the molecular weight Mw) of CH₄:
Mw(CH₄) = 12 g/mol C + (1 g/mol H x 4) = 16 g/mol
moles CH₄ = mass CH₄/Mw(CH₄)= 2.50 g/(16 g/mol) = 0.15625 mol CH₄
Now, we divide the heat released into the moles of CH₄ to obtain the enthalpy per mole of CH₄:
ΔHc = heat/mol CH₄ = 125 kJ/(0.15625 mol) = 800 kJ/mol
Therefore, the enthalpy of combustion of methane is -800 kJ/mol (the minus sign indicated that the heat is released).
Answer:
<em>Molecules of different gases with the same mass and temperature always have the same average kinetic energy - E.</em>
Answer:
A reaction rate is a measure of how fast a reactant disappears or a product forms during a reaction.
Explanation:
It is usually defined as the change in concentration per unit time:
Δ(concentration)/Δt
The units are (moles per litre) per second.
In symbols, the units are mol/(L·s) or mol·L^-1 s^-1.
