Answer:
moles HCl = 101.2 g /36.461 g/mol=2.78
[H+]= 2.78 mol/ 150 L =0.0185
pH = - log 0.0185=1.73
1.73 is the answer
Equation for Half life :
A = a(0.5)^(t/h)
A is current amount, "a" is initial amount, h is halflife, t is time
5 = 40(0.5)^(t/1.3x10^9)
5/40 = (0.5)^(t/1.3x10^9)
take the log of both sides , power rule
Log(5/40) = (t/1.3x10^9) * Log(0.5)
(1.3x10^9) * Log(5/40) / Log(0.5) = t
3.9x10^9 years = t
And if you think about what a half life is, the time it take for the amount to reduce to half.
40/2 = 20
20/2 = 10
10/2 = 5
It went through 3 half-lifes
3 * 1.3x10^9 = 3.9x10^9 years
Answer:
<h2>mass = 524.7 g</h2>
Explanation:
The density of a substance can be found by using the formula
Making mass the subject we have
<h3>mass = Density × volume</h3>
From the question
Density = 1.98 g/mL
volume = 265 mL
Substitute the values into the above formula and solve for the mass
That's
mass = 1.98 × 265
We have the final answer as
<h3>mass = 524.7 g</h3>
Hope this helps you
The wavelength is obtained as 122 nm. Option A
<h3>What is the wavelength?</h3>
We know that from the Bohr model of the atom, an electron can move from a higher energy level to a lower energy level or from a lower energy level to a higher energy level. This is the idea of energy quantization as put forward by Neill Bohr.
The wavelength can be obtained by the use of the formula;
1/λ = RH(1/n^2initial - 1/n^2 final)
λ = wavelength of the emitted light
RH = Rydberg's constant
n intial = initial energy level
nfinal = final energy level
Thus;
1/λ = 1.09 * 10^7(1/1^2 - 1/2^2)
1/λ = 1.09 * 10^7( 1 - 0.25)
λ = 122 nm
Learn more about the wavelength:brainly.com/question/13533093
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Answer:
B. ice and glaciers
Explanation:
The majority of total freshwater on Earth, about 68.7 percent, is held in ice caps and glaciers.
