Answer:
56
Explanation:
The mass number of an atom is a sum of its number of protons and neutrons. Iron (Fe) has an atomic number of 26. This means that it has 26 protons. Since we know it has 26 protons and are told it has 30 neutrons. The mass number of this atom of Iron is 26+30 = 56
Hope this helped!
<span>Air pressure decreases as you move higher in the atmosphere. Think of a column of air directly over your body. ... Just as air pressure decreases with altitude, so does the density of air.</span>
Answer:
Explanation:
The usefulness of a buffer is its ability to resist changes in pH when small quantities of base or acid are added to it. This ability is the consequence of having both the conjugate base and the weak acid present in solution which will consume the added base or acid.
This capacity is lost if the ratio of the concentration of conjugate base to the concentration of weak acid differ by an order of magnitude. Since buffers having ratios differing by more will have their pH driven by either the weak acid or its conjugate base .
From the Henderson-Hasselbach equation we have that
pH = pKa + log [A⁻]/[HA]
thus
0.1 ≤ [A⁻]/[HA] ≤ 10
Therefore the log of this range is -1 to 1, and the pH will have a useful range of within +/- 1 the pKa of the buffer.
Now we are equipped to answer our question:
pH range = 3.9 +/- 1 = 2.9 through 4.9
Answer:
T = 9.875K
Explanation:
The ideal gas Law is PV = nRT.
P = Pressure
V = Volume
n = amount of substance
R = 8.314 J/(K. mol)
T = Temperature in Kelvin
22g CO2
CO2 Molar Mass = 44g/mol
C = 12g/mol
O = 16g/mol
P = 0.8210atm
V = 50L
PV = nRT
0.8210 x 50 = 8.314 x 0.5 x T
41.05 = 4.157T
T = 41.05/4.157
T = 9.875K
