Answer:
Number of moles = 0.075 mol
Explanation:
Volume = 500.0 mL = 0.5 (Converting to L by dividing by 1000)
Molarity = 0.15 M
Number of moles = ?
The relationship between the quantities is given as;
Molarity = Number of moles / Volume
Number of moles = Molarity * Volume
Number of moles = 0.15 * 0.5
Number of moles = 0.075 mol
1) Chemical reaction: HCN + H₂O → CN⁻ + H₃O⁺.
c(HCN) = 2,2 M = 2,2 mol/L.
pKa(HCN) = 9,21.
Ka = 6,16·10⁻¹⁰.
[CN⁻] = [H₃O⁺] = x.
[HCN<span>] = 2,2 M - x.
</span>Ka = [CN⁻] · [H₃O⁺] / [HCN].
6,16·10⁻¹⁰ = x² / 2,2 M -x.
Solve quadratic equation: [CN⁻] = [H₃O⁺] = 0,0000346 M.
[HCN] = 2,2 M - 0,0000346 M = 2,199 M.
2) pH = - log[H₃O⁺].
pH = -log( 0,0000346 M).
pH = 4,46.
Hydrocyanic acid and hydronium ion (H₃O⁺) are acids. Cyanide anion (CN⁻) is the strongest base in the system, cyanide anion accept protons in chemical reaction.
pKb = pKw - pKa.
pKb = 14 - 9,21 = 4,79.
Answer:
Cu(s) + N₂(g) + 2O₂(g) ⟶ Cu(NO₂)₂(s)
Answer: A volume of 0.592 L of methane gas is required at 237 K and 101.33 kPa when the volume is decreased to 0.50 L, with a temperature of 300 K and a pressure of 151.99 kPa.
Explanation:
Given: 
= 237 K, 
= 101.33 kPa, 
= ?
= 300 K, 
= 151.99 kPa, 
= 0.50 L
Formula used is as follows.
Substitute the values into above formula as follows.
Thus, we can conclude that a volume of 0.592 L of methane gas is required at 237 K and 101.33 kPa when the volume is decreased to 0.50 L, with a temperature of 300 K and a pressure of 151.99 kPa.
Answer:
4.10x10⁻³g.
4.10 mg.
Explanation:
Hello,
In this case, considering the given number, we can see it has two digits after the first nonzero digit that is four (4) which is also at the third decimal place, it means that the scientific notation has a negative power as it is at the left of the given zeros, therefore it is:
4.10x10⁻³g.
Moreover, since the proper prefix for the factor x10⁻³ is milli, the number with prefix is:
4.10 mg.
Best regards.
