Answer:
Explanation:
Hello,
In this case, for the calculation of the pH of the given buffer we need to use the Henderson-Hasselbach equation:
![pH=pKa+log(\frac{[base]}{[acid]} )](https://tex.z-dn.net/?f=pH%3DpKa%2Blog%28%5Cfrac%7B%5Bbase%5D%7D%7B%5Bacid%5D%7D%20%29)
Whereas the pKa for benzoic acid is 4.19, the concentration of the base is 0.15 M (sodium benzoate) and the concentration of the acid is 0.25 M (benzoic acid), therefore, the pH turns out:
Regards.
Answer:
B. Equal to 7.
Explanation:
Hydrobromic acid is a strong acid that decreases pH and ammonia is a strong base that increases pH.
As the initial pH of water is 7,0 the addition of 35.0mL of 0.400M HBr will produce a pH less than 7,0. But, the same effect of decreasing pH is reverted for the addition of 35.0mL of 0.400M HNO3.
That means the net effect of the two addition is to have a pH:
B. Equal to 7.
I hope it helps!
Answer:
B = mass, height
Gravitational potential energy is a function of the mass ans the height of an object.
Explanation:
The formula for gravitational potential energy is
GPE = mgh
m = mass in kilogram
g = acceleration due to gravity
h = height in meter above the ground
Formula:
GP.E = mgh
Consider the following example:
A crane lifts a 75kg mass a height of 8 m. Calculate the gravitational potential energy gained by the mass:
Formula:
GP.E = mgh
Now we will put the values in formula.
g = 9.8 m/s²
GP.E = 75 Kg × 9.8 m/s²× 8 m
GP.E = 5880 Kg.m²/s²
Kg.m²/s² = j
GP.E = 5880 j
Answer : The molar mass of unknown substance is, 39.7 g/mol
Explanation : Given,
Mass of unknown substance = 9.56 g
Volume of solution = 100.0 mL
Molarity = 2.41 M
Molarity : It is defined as the number of moles of solute present in one liter of volume of solution.
Formula used :
Now put all the given values in this formula, we get:
Therefore, the molar mass of unknown substance is, 39.7 g/mol
Answer: chemical
not 100% sure
