Answer: Between 1 and 2.
Explanation:
Half life is the amount of time taken by a radioactive material to decay to half of its original value.
............(1)
where,
a = amount of reactant left after n-half lives = 40
= Initial amount of the reactant = 100
n = number of half lives
Putting in the values we get:
taking log on both sides
Thus half-lives that have elapsed is between 1 and 2
C. A nearly identical image.
Answer:
mass CaI2 = 23.424 Kg
Explanation:
From the periodic table we obtain for CaI2:
⇒ molecular mass CaI2: 40.078 + ((2)(126.90)) = 293.878 g/mol
∴ mol CaI2 = (4.80 E25 units )×(mol/6.022 E23 units) = 79.708 mol CaI2
⇒ mass CaI2 = (79.708 mol CaI2)×(293.878 g/mol) = 23424.43 g
⇒ mass CaI2 = 23.424 Kg
Answer:
88,7 mL of solution
Explanation:
Molarity (Represented as M) is an unit of chemical concentration that is defined as the ratio between moles of solute per liters of solution, that is:
Molarity = moles of solute / Liters of solution
If molarity of KCN solution is 0,0820M and moles of KCN are 7,27x10⁻³ moles:
0,0820M = 7,27x10⁻³ moles / Liters of solution
Liters of solution = 0,0887L = <em>88,7 mL of solution</em>
I hope it helps!
Answer is: the missing pressure is 1088.66 mmHg.
Gay-Lussac's Law states that the pressure of a given amount of gas held at constant volume is directly proportional to the Kelvin temperature.
p₁/T₁ = p₂/T₂.
p₁ = 960 mmHg; pressure of the gas.
T₁ = 100°C + 273.15.
T₁ = 373.15 K; temperature of the gas.
T₂ = 150°C + 273.15.
T₂ = 423.15 K.
p₂ = p₁T₂/T₁.
p₂ = 960 mmHg · 423.15 K / 373.15 K.
p₂ = 1088.66 mmHg.