Answer:
1. in the Northern Hemisphere the vernal equinox falls about March 20 or 21, as the Sun crosses the celestial equator going north. In the Southern Hemisphere the equinox occurs on September 22 or 23, when the Sun moves south across the celestial equator.
Explanation:
Hope this helps ^^
I believe the answer is A. Not 100% sure
Answer:
0.16 moles of Carbon
Explanation:
The balanced reaction equation:
+ → + ↑
The mole ratio of Carbon to Iron is 3 : 4 (since Fe2O3 is in excess)
i.e 3 moles of C produces 4 moles of Fe.
If 1 mole of Fe - 55.8g of Fe
? moles - 11.6g of Fe
= = 0.208 moles
But 3 moles of C - 4 moles of Fe
? moles of C - 0.208 moles of Fe
= = 0.16 moles of carbon.
I hope this explanation was clear and useful.
Solution:
We have to use the Henderson-Hasselbalch equation: for this calculation
Henderson–Hasselbalch equation describes the derivation of pH as a measure of acidity by using pKa, the negative log of the acid dissociation constant in biological and chemical systems. The equation is also useful for estimating the pH of a buffer solution and finding the equilibrium pH in acid-base reaction.
The equation is given by:
Here, [HA] is the molar concentration of the un dissociated weak acid, [A⁻] is the molar concentration (molarity, M) of this acid's conjugate base and pKa is −log10 Ka where Ka is the acid dissociation constant, that is:
pH = pKa + log([A^-]/[HA])
We look up the pKa for acetic acid:
pKa = 4.76
Let x = molarity of AcO^- and y = molarity of AcOH: Then we have the following two equations in two unknowns:
(1) x + y = 0.10 M
and
(2) 4.9 = 4.76 + log(x/y)
Further calcite the value of x and y by algebraic method and get the answer.
Answer:
All of them I think
Explanation:
STEM is science, technology, engineering and math, and all of them use that in some aspect