Moles of lead(Pb) = 1.6x10^23/6.02x10^23 = 0.265 moles.
Weight of lead = moles x atomic weight of lead
= 0.265x207.2
= 54.908 grams.
Hope this helps!
Answer:
pH = 1.32
Explanation:
H₂M + KOH ------------------------ HM⁻ + H₂O + K⁺
This problem involves a weak diprotic acid which we can solve by realizing they amount to buffer solutions. In the first deprotonation if all the acid is not consumed we will have an equilibrium of a wak acid and its weak conjugate base. Lets see:
So first calculate the moles reacted and produced:
n H₂M = 0.864 g/mol x 1 mol/ 116.072 g = 0.074 mol H₂M
54 mL x 1L / 1000 mL x 0. 0.276 moles/L = 0.015 mol KOH
it is clear that the maleic acid will not be completely consumed, hence treat it as an equilibrium problem of a buffer solution.
moles H₂M left = 0.074 - 0.015 = 0.059
moles HM⁻ produced = 0.015
Using the Henderson - Hasselbach equation to solve for pH:
ph = pKₐ + log ( HM⁻/ HA) = 1.92 + log ( 0.015 / 0.059) = 1.325
Notes: In the HH equation we used the moles of the species since the volume is the same and they will cancel out in the quotient.
For polyprotic acids the second or third deprotonation contribution to the pH when there is still unreacted acid ( Maleic in this case) unreacted.
Answer:
You are the Cobalt
Explanation:
The least massive metalloid in the fourth period is Germanium, and it have 32 protons. If you have 5 less protons: 32 - 5 = 27 protons. The element with 27 protons is Cobalt
Answer:
P = 27.9 atm
Explanation:
Given data:
Mass of CO₂ = 25 g
Temperature = 25°C (25+273.15 K = 298.15 K)
Volume of gas = 0.50 L
Pressure of gas = ?
Solution:
Firs of all we will calculate the number of moles of gas,
Number of moles = mass/molar mass
Number of moles = 25 g/ 44 g/mol
Number of moles = 0.57 mol
Pressure of gas :
PV = nRT
P= Pressure
V = volume
n = number of moles
R = general gas constant = 0.0821 atm.L/ mol.K
T = temperature in kelvin
P × 0.50 L = 0.57 mol × 0.0821 atm.L/ mol.K × 298.15 K
P = 13.95 atm.L/ 0.50 L
P = 27.9 atm
The IUPAC name of NO is nitric oxide. It is one of the many oxides of nitrogen. It is a colorless gas under standard temperature and pressure. It found great application in the combustion of fossil fuels in power plants. This substance is produced naturally by lightning.
