Answer:
8.9357.
Explanation:
So, let us dive right into the solution to the above problem;
We have that the volume of the solution = 0.450 L.
The first thing to do is to determine the number of moles by using the formula below:
Pressure × volume = number of moles × gas constant × temperature.
Therefore, making the number of moles the subject of the formula we have;
Number of moles = (pressure × volume)/ has constant × temperature.
Number of moles of NH3=( 735 × 7.50 )/ 62.4 × 295 = 0.2995 moles.
The number of moles of HCl =
0.450 × 0.450 = 0.2025 moles.
Molarity of HCl = 0.2025 moles/ 0.450 L = 0.45M.
The molarity of {OH^-} = (0.2995 moles - 0.2025 moles) /0.450 = 0.097/0.450 = 0.2156 M.
Therefore, kb = 1.8 × 10^-5 = [ 0.450] [OH^-] / [ 0.2156 M] = 0.000008624.
[OH^-] = 0.000008624.
Hence, pOH = 5.0643.
pH = 14 - 5.0643 = 8.9357.
Answer:
The answer is B on edge
Explanation:
Here are my notes on this section for anyone that needs them
Enthalpy and State Function
Bonds contain potential energy. Breaking and forming bonds involves energy. Reactants and products contain energy. Enthalpy (H) is a measure of heat and internal energy in a system.
A state function is a quantity whose change in magnitude during a process depends only on the beginning and end points the process, not the path taken between them. Enthalpy change during reaction depends only on the identity of reactants and products and their initial and finial condition
Enthalpy of Formation
enthalpy of formation (Hf) is the energy absorbed or released when a pure substance forms from elements in their standard states
Units: kJ/mol, kcal/mol
Standard state is the natural state of an element at 1 atm (atmosphere of pressure) and 25 degrees celsius. Hf for a pure element in its standard state is 0 kJ/mol.
H (hydrogen): H2(g)
N (nitrogen): N2(g)
O (oxygen): O2(g)
F (fluorine): F2(g)
Cl (chlorine): Cl2(g)
Br (bromine): Br2(l)
Hg (mercury): Hg(l)
Enthalpy of Reaction
Enthalpy of reaction (Hrxn) is energy absorbed or released during a chemical reaction
Hrxn negative: exothermic reaction
Hrxn positive: endothermic reaction
Hess's Law: Hrxn = Σ(ΔHƒ, products) − Σ(ΔHƒ, reactants)
thermochemical equation: the chemical equation that shows the state of each substance involved and the energy change involved in a reaction
Find the kJ/mol of the product and then subtract the kJ/mol of the reactants.
The answer should be 5 cu
Answer : Normally in any chemical reaction, if the enthalpy change i.e. ΔH is positive which means it is greater than zero then it can be called as an Endothermic Reaction.
Whereas, the system under study is absorbing heat that is produced during the reaction. So if ΔH is found to be positive then it can be called as endothermic reaction.
