Answer:
100 g
Explanation:
From the question given above, the following data were obtained:
Original amount (N₀) = 400 g
Time (t) = 4 years
Half-life (t½) = 2 years
Amount remaining (N) =?
Next, we shall determine the number of half-lives that has elapse. This can be obtained as follow:
Time (t) = 4 years
Half-life (t½) = 2 years
Number of half-lives (n) =?
n = t / t½
n = 4 / 2
n = 2
Thus, 2 half-lives has elapsed.
Finally, we shall determine the amount remaining of the radioactive isotope. This can be obtained as follow:
Original amount (N₀) = 400 g
Number of half-lives (n) = 2
Amount remaining (N) =?
N = 1/2ⁿ × N₀
N = 1/2² × 400
N = 1/4 × 400
N = 0.25 × 400
N = 100 g
Thus, the amount of the radioactive isotope remaing is the 100 g.
Answer:
4.00 is the pH of the mixture
Explanation:
The ethyl amine reacts with HNO3 as follows:
C2H5NH2 + HNO3 → C2H5NH3⁺ + NO3⁻
To solve this question we need to find the moles of ethyl amine and the moles of HNO3:
<em>Moles C2H5NH2:</em>
0.0500L * (0.100mol/L) = 0.00500 moles ethyl amine
<em>Moles HNO3:</em>
0.201L * (0.025mol/L) = 0.005025 moles HNO3
That means HNO3 is in excess. The moles in excess are:
0.005025 moles HNO3 - 0.00500 moles ethyl amine =
2.5x10⁻⁵ moles HNO₃
In 50 + 201mL = 251mL = 0.251L:
2.5x10⁻⁵ moles HNO₃ / 0.251L = 9.96x10⁻⁵M = [H+]
As pH = -log [H+]
pH = -log 9.96x10⁻⁵M
pH = 4.00 is the pH of the mixture
Answer:
Bulk matter can exist in three states: gas, liquid, and solid. Gases have the lowest density of the three, are highly compressible, and fill their containers completely
Explanation:
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Answer:
Cr (HSO4)3
Explanation:
its molecular weight is 343.20 g/mol
its molecular formula can also be written as CrH3O12S3
molar mass of Cr (HSO4)3 can be calculated by following method;
atomic mass of Cr = 51.9961 u
atomic mass of H = 1 u
atomic mass of S = 32.065 u
atomic mass of O = 16 u
molar mass of Cr(HSO4)3 = 51.9961+ 1.00784×3 + 32.065×3 + 15.999×12
molar mass of Cr(HSO4)3 =51.9961+3.02352+96.195+ 191.988
molar mass of Cr(HSO4)3 = 343.20 g/mol
Monosaccharides are the simplest unit of carbohydrates. They're composed of carbon, hydrogen, and oxygen atoms, and they cannot be broken down further since they are already in their simplest form. Their general formula is (CH2O)n, where n is any number equal or greater than 3.
