Sodium-25 after 3 minutes : 1.0625 mg
<h3>Further explanation</h3>
General formulas used in decay:
T = duration of decay
t 1/2 = half-life
N₀ = the number of initial radioactive atoms
Nt = the number of radioactive atoms left after decaying during T time
<h3 />
No=8 mg
t1/2=60 s
T=3 min=180 s
Answer:
Explanation:
![\rm MX(s) $\, \rightleftharpoons \,$ M$^{+}$(aq) + $^{-}$(aq); $K_{\text{sp}}$ = [M$^{+}$][X$^{-}$]\\\\\text{$K_{\text{sp}}$ gives us information on}\\\\\boxed{\textbf{ the equilibrium between the solid and its ions in solution}}](https://tex.z-dn.net/?f=%5Crm%20MX%28s%29%20%24%5C%2C%20%5Crightleftharpoons%20%5C%2C%24%20M%24%5E%7B%2B%7D%24%28aq%29%20%2B%20%24%5E%7B-%7D%24%28aq%29%3B%20%24K_%7B%5Ctext%7Bsp%7D%7D%24%20%3D%20%5BM%24%5E%7B%2B%7D%24%5D%5BX%24%5E%7B-%7D%24%5D%5C%5C%5C%5C%5Ctext%7B%24K_%7B%5Ctext%7Bsp%7D%7D%24%20gives%20us%20information%20on%7D%5C%5C%5C%5C%5Cboxed%7B%5Ctextbf%7B%20the%20equilibrium%20between%20the%20solid%20and%20its%20ions%20in%20solution%7D%7D)
It tells us nothing about the amount of precipitate that will form or the temperature at which the equilibrium occurs.
Answer:
Percent yield = 89.1%
Explanation:
Based on the equation:
Cl₂ + 2KI → 2KCl + I₂
<em>1 mole of Cl₂ reacts with 2 moles of KI to produce to moles of KCl</em>
<em />
To solve this quesiton we must find the moles of each reactant in order to find the limiting reactant. With the limiting reactant we can find the moles of KCl and the mass:
<em>Moles Cl₂:</em>
8x10²⁵ molecules * (1mol / 6.022x10²³ molecules) = 133 moles
<em>Moles KI -Molar mass: 166.0028g/mol-</em>
25g * (1mol / 166.0028g) = 0.15 moles
Here, clarely, the KI is the limiting reactant
As 2 moles of KI produce 2 moles of KCl, the moles of KCl produced are 0.15 moles. The theoretical mass is:
0.15 moles * (74.5513g / mol) =
11.2g KCl
Percent yield is: Actual yield (10.0g) / Theoretical yield (11.2g) * 100
<h3>Percent yield = 89.1%</h3>
<span>i get 3.19x10^20 atoms
</span>
Given reactions:
(A) 6CO2(g) + 6H2O(l) + sunlight → C6H12O6(aq) + 6O2(g)
(B) 2H2(g) + O2(g) → 2H2O(g) + energy
Exothermic reactions are those which proceed with the release of heat/energy. In contrast, endothermic reactions proceed with the absorption of energy in the form of heat or light.
Since reaction A required sunlight, it is endothermic. Reaction B releases energy, hence exothermic
Ans: (B)
A is endothermic
B is exothermic
