Answer:
You must know the concept of pH of a solution and its relation to the concentration of H+ and OH- ions. pH is a measure of the substance's acidity or basicity. From the definition of Arrhenius, an acid contains an H+ while a base contains a OH- ion. From this definition, we can say that an acidic substance has a higher concentration of H+ ions. Now, I'll introduce here that pH is the value of the negative logarithm of the concentration of H+. In equation,
pH = -log[H+]
The term pOH is therefore also, pOH = -log[OH-]. Therefore, the relationship that connects the two negative logarithms is:
pH + pOH = 14
The pH scale starts from 1 being the most acidic to 14 being the most basic. The neutral pH is 7. Thus, for a pH of 7, the H+ and the OH- concentrations are equal.
pH = 7 = -log[H+]
[H+] = 1×10⁻⁷ mol/L = [OH-]
Since the concentrations are equal, the ratio is equal to 1.
Answer:
Solution given:
1 mole of KCl
22.4l
1 mole of KCl
74.55g
we have
0.14 mole of KCl
74.55*0.14=10.347g
74.55g of KCl
22.4l
10.347 g of KCl
22.4/74.55*10.347=3.11litre
volume of each solution contains 0.14 mol of KCl contain 3.11litre.
Answer:
Example that involves phase change in which heat energy is released by substance:
Explanation:
If heat is removed from a substance, such as in freezing and condensation, then the process is exothermic. In this instance, heat is decreasing the speed of the molecules causing them move slower (examples: liquid to solid; gas to liquid). These changes release heat to the surroundings.3 days ago
Solid → Liquid: Melting or fusion
Gas → Liquid: Condensation
Liquid → Gas: Vaporization
Liquid → Solid: Freezing
Answer:
Percentage mass of copper in the sample = 32%
Explanation:
Equation of the reaction producing Cu(NO₃) is given below:
Cu(s)+ 4HNO₃(aq) ---> Cu(NO₃)(aq) + 2NO₂(g) + 2H₂O(l)
From the equation of reaction, 1 mole of Cu(NO₃) is produced from 1 mole of copper. Therefore, 0.010 moles of Cu(NO₃) will be produced from 0.010 mole of copper.
Molar mass of copper = 64 g/mol
mass of copper = number of moles * molar mass
mass of copper = 0.01 mol * 64 g/mol = 0.64 g
Percentage by mass of copper in the 2.00 g sample = (0.64/2.00) * 100%
Percentage mass of copper in the sample = 32%
Answer:
colorless
Explanation:
The ferric ion reacts with the thiocyanate, which reduces the concentration of Thiocyanate.