Answer:
2.68
Explanation:
At the solution, the number of moles of each substance (acid and conjugate base) is the volume multiplied the concentration
nHNO₂ = 0.50 L * 0.85 mol/L = 0.425 mol
nNO₂⁻ = 0.50 L * 0.61 mol/L = 0.305 mol
At the buffer, the substances are in equilibrium. When HBr is added, it dissociantes in H⁺ and Br⁻, and the H⁺ will react with NO₂⁻ to form more HNO₂. So, NO₂⁻ will be consumed and HNO₂ will be formed at a 1:1:1 reaction:
nH⁺ = nHBr = 0.15 mol
nNO₂⁻ = 0.305 - 0.15 = 0.155 mol
nHNO₂ = 0.425 + 0.15 = 0.575 mol
The pH of a buffer can be calculated by the Handerson-Halsebach equation:
pH = pKa + log[A⁻]/[HA]
Where [A⁻] is the concentration of the conjugate base, and [HA], the concentration of the acid. Because the volume is the same, it can be used the number of moles:
pH = 3.25 + log (0.155/0.575)
pH = 2.68
Greater rainfall has an greater increase on the rate of chemical weathering. Rain is a form of precipitation.
NI(s)->NI^2+(aq)+2e^-(oxidation)
-2.7 × 10^2 is the result of the equation.
Answer: Pentane
Explanation: According to the IUPAC(International Union of Pure and Applied Chemistry) the name of this compound will be pentane. This compound belongs to the alkane category, which has single bond between the carbon atoms. This naming is done on the basis of the number of carbon atoms and the nature of the chemical bond between the carbon atoms.
Word roots are selected based on the number of carbon atoms
1 C atom = Meth
2 C atom = Eth
3 C atom = Prop
4 C atom = But
5 C atom = Pent
6 C atom = Hex
7 C atom = Hept
8 C atom = Oct
9 C atom = Non
10 C atom = Dec
Suffixes are added based on the nature of chemical bond between the carbon atoms.
Word root + suffix (here: ane)