Example 1: Crushing a can.
Type of change:
Developmental – May be either planned or emergent; it is first order, or incremental. ...
Transitional – Seeks to achieve a known desired state that is different from the existing one. ...
Transformational – Is radical or second order in nature.
Answer:
Final pH: 9.49.
Round to two decimal places as in the question: 9.5.
Explanation:
The conjugate of B is a cation that contains one more proton than B. The conjugate of B is an acid. As a result, B is a weak base.
What's the pKb of base B?
Consider the Henderson-Hasselbalch equation for buffers of a weak base and its conjugate acid ion.
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.
.

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What's the new salt-to-base ratio?
The 0.005 mol of HCl will convert 0.005 mol of base B to its conjugate acid ion BH⁺.
Initial:
;
.
After adding the HCl:
;
.
Assume that the volume is still 0.5 L:
.
.
What's will be the pH of the solution?
Apply the Henderson-Hasselbalch equation again:
![\displaystyle \text{pOH} = \text{pK}_b + \log{\frac{[\text{Salt}]}{[\text{Base}]}} = 4.64613 + \log{\frac{0.760}{1.04}} = 4.50991](https://tex.z-dn.net/?f=%5Cdisplaystyle%20%5Ctext%7BpOH%7D%20%3D%20%5Ctext%7BpK%7D_b%20%2B%20%5Clog%7B%5Cfrac%7B%5B%5Ctext%7BSalt%7D%5D%7D%7B%5B%5Ctext%7BBase%7D%5D%7D%7D%20%3D%204.64613%20%2B%20%5Clog%7B%5Cfrac%7B0.760%7D%7B1.04%7D%7D%20%3D%204.50991)
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The final pH is slightly smaller than the initial pH. That's expected due to the hydrochloric acid. However, the change is small due to the nature of buffer solutions: adding a small amount of acid or base won't significantly impact the pH of the solution.
N2 + 3H2 ------> 2NH3
According to the equation;
3 mol of hydrogen will produce 2mol of ammonia.
1 mol of hydrogen _____________________?
= 2 × 1/3
= 0.67 mol
Let's examine the given choices:
V = (4/3)*pi*(r)^3 is the rule to calculate the volume of the sphere
V = (1/3)*pi*(r)^2*h is the rule to calculate the volume of the cone
V = s^3 is the rule to calculate volume of the cube
V = pi*(r)^2*h is the rule to calculate volume of the cylinder
Now, the ball can be treated as a perfect sphere, therefore, to calculate its volume we will use the rule of the volume of sphere.
Based on this, the correct choice is:
V = (4/3)*pi*(r)^3
Answer:
THE PARTIAL PRESSURE OF OXYGEN GAS IN THE CONTAINER IS 92.67kPa WHICH IS OPTION B.
Explanation:
To calculate the partial pressure of oxygen gas collected over water, we use
Ptotal = Poxygen + P water
It is worthy to note that when oxygen is collected over water, it is mixed with water vapor and the total pressure in the container will be the sum of the pressure exerted by the oxygen gas and that of the water vapor at that given temperature.
At 20 C, the vapor pressure of water as given in the question is 2.33 kPa.
Using the above formula,
Ptotal = Poxygen + P water
Substituting for Poxygen, we have;
Poxygen = Ptotal - P water vapor
P oxygen = 95 .00 kPa - 2.33 kPa
P oxygen = 92.67 kPa.
The partial pressure of oxygen gas in the container is hence, 92.67kPa.