Local winds are mall scale convective winds of local
origin caused by temperature differences. Prevailing winds are winds that blow
predominantly from a single general
direction over a particular point on the Earth’s surface.
<span>stereochemistry and reaction mechanisms</span>
卂几丂山乇尺
Point "C" is correct and all the remaining are false.
Note, HomeAtomic and HeteroAtomic compounds are the types of compounds, but not homogenous and heterogenous.
Answer:
a. pH = 4.56
b. Change in pH = 0.85
c. Change in pH = 5.4
Explanation:
a. The pKa of lactic buffer is: 3.86.
Using Henderson-Hasselbalch formula for the lactic buffer:
pH = 3.86 + log [Lactate] / [Lactic acid]
<em>Where [] is molarity of each compound but could be taken as moles</em>
<em />
Replacing:
pH = 3.86 + log [0.050 moles] / [0.010 moles]
<em>pH = 4.56</em>
<em />
b. The HCl added reacts with Lactate producing lactic acid. Moles of HCl are:
5x10⁻³L * (0.5mol /L) = 0.025 moles HCl
Moles of lactate: 0.050moles - 0.025 moles = 0.025 moles
Moles lactic acid: 0.010 moles + 0.025 moles = 0.035 moles
pH = 3.86 + log [0.025 moles] / [0.035 moles]
<em>pH = 3.71</em>
Change in pH = 4.56 - 3.71 = 0.85
c. 1L of pure water has a pH of 7. 0.025 moles of HCl = 0.025 moles H⁺ in 1.005L:
0.025 mol / 1.005L = 0.0249M = [H⁺]
As pH = -log [H⁺]
pH = 1.6
Change in pH = 7.0 - 1.6 = 5.4
Hey there!
A half-life means after a certain amount of time, half of that substance will gave decayed after that time.
So, we divide the 120 atom sample in half 3 times.
120 ÷ 2 = 60
60 ÷ 2 = 30
30 ÷ 2 = 15
There will be 15 atoms of the radioactive sample remaining after three half lives.
Hope this helps!