Answer:
Explanation:
NH₄NO₃ = NH₄⁺ +NO₃⁻
heat released by water = msΔ T
m is mass , s is specific heat and ΔT is fall in temperature
= 50 x 4.18 x ( 22 - 16.5 ) ( mass of 50 mL is 50 g )
= 1149.5 J .
This heat will be absorbed by the reaction above .
q for the reaction = + 1149.5 J
2 )
molecular weight of NH₄NO₃ = 80
No of moles reacted = 5/80 = 1 / 16 moles.
3 )
5 g absorbs 1149.5 J
80 g absorbs 1149.5 x 16 J
= 18392 J
= 18.392 kJ.
= + 18.392 kJ
ΔH = 18.392 kJ / mol
Collision with a high-speed particle
Cobalt because it has an atomic mass of 58 and 33 neutrons.
Answer:
pH = 2.18
Explanation:
Perchloric acid (HClO₄) is a strong acid. This means that in an aqueous solution it completely dissociates into H⁺ and ClO₄⁻ species.
First we <u>convert 249 mg HClO₄ into moles</u>, using its <em>molecular weight</em>:
- 249 mg HClO₄ ÷ 100.46 mg/mmol = 2.49 mmol HClO₄
<em>Because it is a strong acid</em>, 2.49 mmol HClO₄ = 2.49 mmol H⁺
We <u>calculate the molar concentration of H⁺</u>:
- 2.49 mmol H⁺ / 380 mL = 6.52x10⁻³ M
Finally we <u>calculate the pH of the solution</u>:
- pH = -log[H⁺] = -log(6.52x10⁻³)
