New answers tagged

3

First, we have some things to consider and they are: the specific heat of water; the latent heat of vaporization of water; how the terms mentioned above are compared to each other. The specific heat of water is $\pu{4200 J kg-1 K-1}$ and it means that it takes $\pu{4200 kJ}$ amount of heat to increase the temperature of $\pu{1 kg}$ water by $\pu{1 K}.$ On ...


3

Using vibrational partition functions to define the reaction rate constant produces an equation of the form $\displaystyle k=aT^be^{-\Delta U_0^\mathrm{O}/(RT)}$ where $a,b$ are constants independent of $T$ and $\Delta U_0^\mathrm{O}$ is the difference in zero point energies at the transition state compared to reactant, this is related to what is commonly ...


0

Enthalpy is slightly affected by isotope composition, but mostly below enthalpy measurement errors. Generally, the standard enthalpy is considered for natural mixture of stable isotopes, unless considered for particular isotope explicitly.


2

There are no two halfs of oxygen. The half denotes that there is $\frac{1}{2}$ a mole of oxygen produced for every mole of $\ce{PbO}$ (or $\ce{CO}$) reacting. So there is no such "joining of oxygen halves" going on.


0

The heat of reaction of a mixture is defined as the extent of reaction, $\xi$ times the enthaply of reaction, $\Delta H_{rxn}$, $$Q_{rxn} =\xi\Delta H_{rxn} = \sum^n_{i=1}\nu_iH_{f,i}^{o} =\sum^{n,products}_{i=1}\|\nu_i\|H_{f,i}^{o} - \sum^{m,reactants}_{i=1}\|\nu_i\|H_{f,i}^{o} $$ For a reaction system, $$\ce{4NH_3(g) + 5O_2(g) -> 6H_2O(g) + 4NO(g)}$$ ...


0

Exothermic reactions are those reactions in which heat is evolved. If we are breaking a bond we need to energy to break it so those are endothermic reactions. But when a bond gets formed energy gets liberated those are known as exothermic reactions. In the formation of ammonia three nitrogen - hydrogen bonds are formed which results in the form of loss of ...


Top 50 recent answers are included