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Chlorine has two isotopes, Cl-35 and Cl-37 with the average atomic mass 35.5. what is the percentage composition of Cl-35 and Cl

Novosadov [1.4K]

Answer:

75% of Cl-35 and 25% of Cl-37

Explanation:

Equation to find the mass number of an element. repeat the brackets for however many isotopes it has.

$\frac{(abundance \: \times \: mr) \: + \: (abundance \: \times \: mr)}{100}$

$\frac{(75 \times 35) + (25 \times 37)}{100} = 35.5$

You can try guess it because 35.5 is closer to 35 than 37 so it has a higher abundance of Cl-35

4 0

3 years ago

Sample of gas initially occupies 4.25 L at a pressure of 0.850 atm at 23.0°C. What will the volume be if the temperature is chan

Aliun [14]

Answer: 2.34 L

Explanation:

Combined gas law is the combination of Boyle's law, Charles's law and Gay-Lussac's law.

The combined gas equation is,

$\frac{P_1V_1}{T_1}=\frac{P_2V_2}{T_2}$

where,

$P_1$ = initial pressure of gas = 0.850 atm

$P_2$ = final pressure of gas = 1.50 atm

$V_1$ = initial volume of gas = 4.25 L

$V_2$ = final volume of gas = ?

$T_1$ = initial temperature of gas = $23.0^oC=273+23.0=293.0K$

$T_2$ = final temperature of gas = $11.5^oC=273+11.5=284.5K$

Now put all the given values in the above equation, we get:

$\frac{0.850\times 4.25}{293.0K}=\frac{1.50\times V_2}{284.5}$

$V_2=2.34L$

Thus the final volume will be 2.34 L

3 0

3 years ago

‏A second - order reaction has a rate constant of 0.06 M min - 1 . It takes min for the reactant concentration to decrease from

alekssr [168]

Answer:

Choice D. Approximately $61.2$ minutes.

Explanation:

The reaction rate of a second-order reaction is proportional to the square of one of its reactants.

Let $y$ denote the concentration of that reactant (in $\rm M$ .)
Let $t$ denote time (in minutes.)

Let $k$ denote the rate constant of this reaction. Assume that $y_0$ is the concentration of that reactant at the beginning of this reaction (when $t = 0$ .) Because this reaction is of second order, it can be shown that:

$\displaystyle y = \frac{1}{k\, t + (1/y_0)}$ .

The question states that the rate constant here is $0.06\; \rm M\cdot min^{-1}$ . Hence, $k = 0.06$ . For simplicity, assume that $t = 0$ when the concentration is $0.13\; \rm M$ . Therefore, $y_0 = 0.13$ . The equation for concentration $y$ at time $t$ would become:

$\displaystyle y = \frac{1}{\underbrace{0.06}_{k}\, t + (1/\underbrace{0.13}_{y_0})}$ .

The goal is to find the time at which the concentration is $0.088$ . That's the same as solving this equation for $t$ , given that $y = 0.088$ :

$\displaystyle \frac{1}{0.06\; t + (1/0.13)} = 0.088$ .

$t \approx 61.2$ .

In other words, it would take approximately $61.2$ minutes before the concentration of this second-order reactant becomes $0.088\; \rm M$ .

6 0

3 years ago

60cm³ of hydrogen are sparked with 20cm³ of oxygen at 100°c and 1 atmosphere. The total volume of the residual gasses is?

Gnesinka [82]

Answer:

Options

*A) 60 cm3 = Correct.* This is the answer

B) 10 cm3

C) 40 cm3

D) 30 cm3

E) 70 cm3

Explanation:

5 0

2 years ago

The atomic number is the _____. atomic mass number of neutrons protons plus the neutrons number of protons

SSSSS [86.1K]

It's the number of protons.
The table of elements organizes the elements by their number of protons/the atomic number as the number of protons of an element is fixed, unlike the number of electrons and neutrons.

5 0

3 years ago

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