The answer is A. Volcanoes and earthquakes often occur near place boundaries. Volcanoes are exit points for heat from the Earth's core. And Earthquakes are caused by the tectonic places colliding along another one. For example one tectonic plate would be slowly moving south, and another next to it could collide with the South-going plate while going North, and that is what causes Earthquakes.
<span>Answer is: pH of solution of sodium cyanide is 11.3.
Chemical reaction 1: NaCN(aq) → CN</span>⁻(aq)
+ Na⁺<span>(aq).
Chemical reaction 2: CN</span>⁻ +
H₂O(l) ⇄ HCN(aq) + OH⁻<span>(aq).
c(NaCN) = c(CN</span>⁻<span>)
= 0.021 M.
Ka(HCN) = 4.9·10</span>⁻¹⁰<span>.
Kb(CN</span>⁻) = 10⁻¹⁴ ÷
4.9·10⁻¹⁰ = 2.04·10⁻⁵<span>.
Kb = [HCN] · [OH</span>⁻]
/ [CN⁻<span>].
[HCN] · [OH</span>⁻<span>] =
x.
[CN</span>⁻<span>] = 0.021 M - x..
2.04·10</span>⁻⁵<span> = x² / (0.021 M
- x).
Solve quadratic equation: x = [OH</span>⁻<span>] = 0.00198 M.
pOH = -log(0.00198 M) = 2.70.
pH = 14 - 2.70 = 11.3.</span>
It starts with a cation and ends with a nonmetal anion. To recap, cations are your positively charged elements and anions are negatively change and usually with the ending “ide”. For example, potassium a metal and chlorine a nonmetal (KCl) would form the word potassium chloride.
Answer:
Explanation:
Here is ur answer what you wanna do first is calculate the first and second numbers and letters this should be ur answer = -394 + 2 x (-242) - (-75) + 2 x 0 = -803 kJ/mol