Answer:
0.371
Explanation:
number of moles = mass / Ar
= 23.8g / 32.1 + (16.0 × 2)
= 0.37129485179 = 0.371 (3 s.f).
hope it helps :)
Ionic is metal and nonmetal
Given that the reactants are the very consituents (elements) of the final compound, the enthalpy change of this reaction is the same heat of formation, Hf.
That means that the enthalpy chage for the reaction is -296.8 kj/mol
Answer:
11.9g remains after 48.2 days
Explanation:
All isotope decay follows the equation:
ln [A] = -kt + ln [A]₀
<em>Where [A] is actual amount of the isotope after time t, k is decay constant and [A]₀ the initial amount of the isotope</em>
We can find k from half-life as follows:
k = ln 2 / Half-Life
k = ln2 / 27.7 days
k = 0.025 days⁻¹
t = 48.2 days
[A] = ?
[A]₀ = 39.7mg
ln [A] = -0.025 days⁻¹*48.2 days + ln [39.7mg]
ln[A] = 2.476
[A] = 11.9g remains after 48.2 days
<em />
