Answer: (A) 
(B) 
Explanation:
(A) As we know that HCl is a strong acid and when it is added to an aqueous solution then it leads to increase in the concentration of hydrogen ions. And, when an acid or base is added to a solution then any resistance by the solution in changing the pH of the solution is known as a buffer.
This means that addition of buffer into the given solution will not cause much change in the concentration of 
in large amount.
As both the buffer components are salt then they will remain dissociated as follows.
Hence, net ionic equation will be as follows.
(B) When we add small amount of sodium hydroxide into the solution then there will occur an increase in concentration of hydroxide ions into the solution. But then due to the presence of buffer there will occur not much change in concentration and the acid will get converted into salt.
The net ionic equation is as follows.
Yes, they are called periods. Pls do you need a confirmation on this and if not what is the question?
Answer:
ΔH = 180.6 kJ
Explanation:
Given that:
N2 (g) + 2O2(g) = 2NO2 (g) ΔH = 66.4 kJ
<u>2NO (g) + O2 (g) = 2NO2 (g) ΔH = -114.2 kJ </u>
N2 (g) + O2 (g) = 2NO (g) ΔH = ????
The subtraction of both equations would yield the unknown ΔH , therefore:
ΔH = 66.4 - ( - 114.2 kJ)
ΔH = 180.6 kJ
2 ways to do this
a. find %Cl in CaCl2
2 x 35.45g/mole = 70.9g Cl
70.9g Cl / 110.9g/mole CaCl2 = 63.93% Cl in CaCl2
0.6963 x 145g = 92.7g = mass Cl
b. determine moles CaCl2 present then mass Cl
145g / 110.9g/mole = 1.31moles CaCl2 present
2moles Cl / 1mole CaCl2 x 1.31moles = 2.62moles Cl
2.62moles Cl x 35.45g/mole = 92.7g Cl
Answer:
Speed, being a scalar quantity, is the rate at which an object covers distance. The average speed is the distance (a scalar quantity) per time ratio. On the other hand, velocity is a vector quantity; it is direction-aware. Velocity is the rate at which the position changes.
