Answer:
w = 164.62 g
Explanation:
molarity of a solution is given as -
Molarity (M) = ( w / m ) / V ( in L)
where ,
m = molecular mass ,
w = given mass ,
V = volume of solution ,
From the question ,
M = 500 mM = 0.5 M
( since , 1 mM = 1 / 100 M)
As we know , the molecular mass of potassium ferricyanide = 329.24 g/ mol
V = vol.of solution = 1 L
w = ?
<u>To find the value of w , using the above formula , and putting the respected values , </u>
Molarity (M) = ( w / m ) / V ( in L)
0.5 = ( w / 329.24 ) / 1 L
w = 164.62 g
Answer:
The amount of heat that is released is -925.2 cal
Explanation:
Calorimetry is the measurement and calculation of the amounts of heat exchanged by a body or a system.
Sensible heat is the amount of heat that a body can receive or release without affecting its molecular structure, that is, it does not change the state (solid, liquid, gaseous). In other words, sensible heat is the amount of heat that a body absorbs or releases without any changes in its physical state.
The equation that allows to calculate heat exchanges is:
Q = c * m * ΔT
Where Q is the heat exchanged by a body of mass m, constituted by a substance of specific heat c and where ΔT is the variation in temperature.
In this case:
- c= 1

- m= 25.7 g
- ΔT= Tfinal - Tinitial= 49 °C - 85 °C= -36 °C
Replacing:
Q= 1
*25.7 g* (-36 C)
Solving:
Q= -925.2 cal
<u><em>The amount of heat that is released is -925.2 cal</em></u>
Answer:
4.77 is the pH of the given buffer .
Explanation:
To calculate the pH of acidic buffer, we use the equation given by Henderson Hasselbalch:
![pH=pK_a+\log(\frac{[salt]}{[acid]})](https://tex.z-dn.net/?f=pH%3DpK_a%2B%5Clog%28%5Cfrac%7B%5Bsalt%5D%7D%7B%5Bacid%5D%7D%29)
![pH=-\log[K_a]+\log(\frac{[salt]}{[acid]})](https://tex.z-dn.net/?f=pH%3D-%5Clog%5BK_a%5D%2B%5Clog%28%5Cfrac%7B%5Bsalt%5D%7D%7B%5Bacid%5D%7D%29)
![pH=-\log[K_a]+\log(\frac{[CH_3CH_2COONa]}{[CH_3CH_2COOH]})](https://tex.z-dn.net/?f=pH%3D-%5Clog%5BK_a%5D%2B%5Clog%28%5Cfrac%7B%5BCH_3CH_2COONa%5D%7D%7B%5BCH_3CH_2COOH%5D%7D%29)
We are given:
= Dissociation constant of propanoic acid = 
![[CH_3CH_2COONa]=0.254 M](https://tex.z-dn.net/?f=%5BCH_3CH_2COONa%5D%3D0.254%20M)
![[CH_3CH_2COOH]=0.329 M](https://tex.z-dn.net/?f=%5BCH_3CH_2COOH%5D%3D0.329%20M)
pH = ?
Putting values in above equation, we get:
![pH=-\log[1.3\times 10^{-5}]+\log(\frac{[0.254 M]}{[0.329]})](https://tex.z-dn.net/?f=pH%3D-%5Clog%5B1.3%5Ctimes%2010%5E%7B-5%7D%5D%2B%5Clog%28%5Cfrac%7B%5B0.254%20M%5D%7D%7B%5B0.329%5D%7D%29)
pH = 4.77
4.77 is the pH of the given buffer .
Nitrogen triiodide<span> is the </span>inorganic compound<span> with the formula </span>NI3<span>. It is an extremely sensitive </span>contact explosive<span>: small quantities explode with a loud, sharp snap when touched even lightly, releasing a purple cloud of iodine vapor; it can even be detonated by </span>alpha radiation. NI3<span> has a complex structural chemistry that is difficult to study because of the instability of the derivatives.</span>
Answer:
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