Answer:
The law is given by the following equation: PV = nRT, where P = pressure, V = volume, n = number of moles, R is the universal gas constant, which equals 0.0821 L-atm / mole-K, and T is the temperature in Kelvin.
Explanation:
Answer:
2.05mg Fe/ g sample
Explanation:
In all chemical extractions you lose analyte. Recovery standards are a way to know how many analyte you lose.
In the problem you recover 3.5mg Fe / 1.0101g sample: <em>3.465mg Fe / g sample. </em>As real concentration of the standard is 4.0 mg / g of sample the percent of recovery extraction is:
3.465 / 4×100 = <em>86,6%</em>
As the recovery of your sample was 1.7mg Fe / 0.9582g, the Iron present in your sample is:
1.7mg Fe / 0.9582g sample× (100/86.6) = <em>2.05mg Fe / g sample</em>
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I hope it helps!
Answer:
Explanation:
Remember that a mole is equal to Avogadro's number: 6.022*10²³ atoms. Also, remember that an atom is made up of protons, neutrons, and electrons. Each element has a different amount of each.
If an element has more of these particles in 1 atom, then the atomic mass will be greater, ultimately making the molar mass (mass of 1 mole) greater.
Silicon has 14 protons, electrons, and neutrons, making its atomic mass 28.085 amu and its molar mass 28.085 grams. However, carbon only has 6 of each particle, so its atomic mass is smaller at 12.011 amu and molar mass is 12.011 grams.
First, we need to get moles of HA =molarity * volume
= 0.1 m * 0.075 L = 0.0075 moles
moles of NaOH = molarity * volume
= 0.1 * 0.03 L = 0.003 moles
from the reaction equation:
HA(aq) + NaOH(aq) → NaA(aq) + H2O(l)
that means the final moles' HA = 0.0075 - 0.003 =0.0045 moles
when the total volume is = 0.075 + 0.03 L = 0.105 L
∴ [HA] = moles / volume
= 0.0045 / 0.105 L = 0.043 m
[A^-] = 0.003 / 0.105 L = 0.029 m
then by using H-H equation:
PH = Pka + ㏒[A^-] / [HA]
by substitution, we can get Pka:
5.5 = Pka+ ㏒ (0.029 /0.043)
∴ Pka = 5.67
when Pka = - ㏒Ka
5.67 = -㏒ Ka
∴Ka = 2 x 10^-6
I am going for C, mark brainliest