Answer:
The correct answer is , Weak bonds are transient and easily reversible.
Explanation:
Molecules or atom that associate to produce a weak bond can interact, and then separate .this is evident in hydrogen bond and vanderwaal force where the combined effect can produce emergent properties.
Example; the hydrogen bonds present in water molecule; when the bonds are broken using heat, the molecules are separated or released in form of vapor, this same molecule can combine again by condensation to produce liquid. showing clearly how transient and reversible the bonds between them is.
For every mole of any substance or element, the total number of atoms is 6.022 x 10^23. This is called the avogadro's number. Hence, for a) for a 0.90 mole copper, the number of atoms is 5.42 x10^23. This also applies for B) which gives silver as given. For c), the number of molecules present in a compound is also the same. Thus, for a,b,and c, the answer is 5.42 x10^23.
Ba(OH)2 is an basic solution. It has more OH- ions than H+ ions. pOH should be calculated to find out its pH
The reaction is
Ba(OH)2 ⇒ Ba2+ (aq) + 2 OH-(aq)
One mole barium hydroxide releases 2 moles hydroxide ions.
Use that ratio to calculate molarity (M) of OH- ions [OH-]. The ratio is 1:2.
0.10 M Ba(OH)2 release 2*0.10 M= 0.02 M OH- ions
[OH-]= 0.02
pOH= - log [OH-] = - log 0.02 = 1.7
Thats not the answer! We found pOH of the solution before titration.
pH and pOH relationship is shown by formula of pH+pOH= 14
pH= 14-pOH
pH= 14-1.7= 12.3
Using the relationship M1V1 = M2V2 where M1 and M2 are the molar concentrations (mol/L or mmol/ml) and V1 and V2 are the volumes of the solutions, we can arrive at the following answer for the given problem:
<span>15.0M (L of stock solution) = 2.35M (0.25L) *all volumes were converted to liters.
L of stock solution = (2.35*0.25)/15.0
Therefore, 0.0392L or 39.17 ml of stock solution is needed. </span>
Endothermic is a chemical change in which heat is taken in (or absorbed).
<It starts out cold and later gets warmer>
Exothermic is a chemical change in which heat is released.
<It starts out hot, but gets cooler>