Answer:
<u>253.33 mmHg</u>
Explanation:
According to Charles' Law,
P₁ / T₁ = P₂ / T₂
P₁T₂ = P₂T₁
P₂ = P₁T₂ / T₁
= 760 x 40 / 30
= 760 x 4/3
= 1013.33 mmHg
Change in Pressure
= 1013.33 - 760
= <u>253.33 mmHg</u>
The pH of the solution at 25 degree celsius of 1.3 × 10⁻⁶ moles of a sample of Sr(OH)₂ is 10.02.
<h3>How do we calculate pH?</h3>
The pH of any solution gives an idea about the acidic and basic nature of the solution and the equation of pH will be represented as:
pH + pOH = 14
Given that,
Moles of Sr(OH)₂ = 1.3 × 10⁻⁶ mol
Volume of solution = 25mL = 0.025L
The concentration of Sr(OH)₂ in terms of molarity = 1.3×10⁻⁶/0.025
= 5.2×10¯⁵M
Dissociation of Sr(OH)₂ takes place as:
Sr(OH)₂ → Sr²⁺ + 2OH⁻
From the stoichiometry of the reaction 1 mole of Sr(OH)₂ produces 2 moles of OH⁻.
Given that the base is a strong base and that it entirely dissociates into its ions, the hydroxide ion concentration is 5.2×10¯⁵×2 = 1.04×10¯⁴ M.
pOH = -log[OH⁻]
pOH = -log(1.04×10¯⁴)
pOH = 3.98
Now we put this value on the first equation we get,
pH = 14 - 3.98 = 10.02
Therefore, the value of pOH is 10.02.
Learn more about pH here:
brainly.com/question/24595796
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The sun is mostly Hydrogen with some helium. It also has traces of other elements like various metals.
Answer:
Half life is 6 years.
Explanation:
T½ = In2 / λ
Where λ = decay constant.
But N = No * e^-λt
Where N = final mass after a certain period of time
No = initial mass
T = time
N = 0.625g
No = 10g
t = 24 years
N = No* e^-λt
N / No = e^-λt
λ = -( 1 / t) In N / No (inverse of e is In. Check logarithmic rules)
λ = -(1 / 24) * In (0.625/10)
λ = -0.04167 * In(0.0625)
λ = -0.04167 * (-2.77)
λ = 0.1154
T½ = In2 / λ
T½ = 0.693 / 0.1154
T½ = 6.00 years.
The half life of radioactive cobalt-60 is 6 years
