<h3><u>Answer;</u></h3>
pOH = 3.08
<h3><u>Explanation;</u></h3>
NX3 + H2O <----> NHX3+ + OH-
Kb = 4.0 x 10^-6
Kb = c(NH₄⁺) · c(OH⁻) ÷ c(NH₃).
c(NH₄⁺) = c(OH⁻) = x.
x² = Kb · c(NH₃)
x² = 4.0 × 10⁻⁶ × 0.175 = 7.0 × 10⁻⁷.
x = c(OH⁻) = √(7.0 × 10⁻⁷)
= 8.367 × 10⁻⁴
pOH = -log(c(OH⁻))
=- log ( 8.367 × 10⁻⁴)
<u>= 3.08</u>
It is called a spring tide
The properties of the given elements are as follows:
Potassium, K;
- State of matter: Solid
- Melting point: 63.5 °C
- Conductivity: Good
- Solubility (H2O): reacts rapidly with water
Iodine, I;
- State of matter: solid
- Melting point: 113.5 °C
- Conductivity: very poor
- Solubility (H2O): negligible
Gold, Au;
- State of matter: solid
- Melting point: 1064 °C
- Conductivity: excellent
- Solubility (H2O): none
Germanium, Ge;
- State of matter: solid
- Melting point: 938.2 °C
- Conductivity: fair
- Solubility (H2O): none
Barium, Ba;
- State of matter: solid
- Melting point: 727 °C
- Conductivity: good
- Solubility (H2O): reacts strongly
Argon, Ar;
- State of matter: gas
- Melting point: -189.4 °C
- Conductivity: none
- Solubility (H2O): negligible
Chlorine Cl;
- State of matter: gas
- Melting point: -101.5 °C
- Conductivity: poor
- Solubility (H2O): slight
Rubidium, Rb;
- State of matter: solid
- Melting point: 39.48 °C
- Conductivity: good
- Solubility (H2O): reacts violently
Silver, Ag;
- State of matter: solid
- Melting point: 961.8 °C
- Conductivity: excellent
- Solubility (H2O): none
Calcium, Ca;
- State of matter: solid
- Melting point: 842 °C
- Conductivity: good
- Solubility (H2O): reacts
Silicon, Si;
- State of matter: solid
- Melting point: 1,410 °C
- Conductivity: intermediate
- Solubility (H2O): none
Xenon, Xe;
- State of matter: gas
- Melting point: -111.8 °C
- Conductivity: very poor
- Solubility (H2O): none
<h3>What are elements?</h3>
Elements are pure substances which are composed of similar atoms.
Elements are defined as substances which cannot be split into simpler substances by an ordinary chemical process.
Elements have different physical and chemical properties and can be classified into:
- metals
- semi-metals
- non-metals
In conclusion, the physical and chemical properties of the elements vary from metals to non-metals.
Learn more about elements at: brainly.com/question/6258301
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Answer:
Number of moles = 0.05 mol
Explanation:
Given data:
Mass of Pb = 10.5 g
Number of moles of Pb = ?
Solution:
Formula:
Number of moles = mass/molar mass
Molar mass of Pb is 207.2 g/mol.
Now we will put the values in formula.
Number of moles = 10.5 g/207.2 g/mol
Number of moles = 0.05 mol
