Need help with this question using dimensional analysis

Data has been collected to show that at a given wavelength in a 1 cm pathlength cell, Beer's Law for the absorbance of Co2 is li

White raven [17]

Answer : The concentration of a solution with an absorbance of 0.420 is, 0.162 M

Explanation :

Using Beer-Lambert's law :

$A=\epsilon \times C\times l$

As per question, at constant path-length there is a direct relation between absorbance and concentration.

$\frac{A_1}{A_2}=\frac{C_1}{C_2}$

where,

A = absorbance of solution

C = concentration of solution

l = path length

$A_1$ = initial absorbance = 0.350

$A_2$ = final absorbance = 0.420

$C_1$ = initial concentration = 0.135 M

$C_2$ = final concentration = ?

Now put all the given value in the above relation, we get:

$\frac{0.350}{0.420}=\frac{0.135}{C_2}$

$C_2=0.162M$

Thus, the concentration of a solution with an absorbance of 0.420 is, 0.162 M

4 0

3 years ago

A gas under a pressure of 74 mmHg and at a temperature of 75°C occupies a 500.0-L container. How many moles of gas are in the co

Leona [35]

Answer : The number of moles of gas present in container are 1.697 mole.

Explanation :

Using ideal gas equation,

$PV=nRT$

where,

P = pressure of gas = 74 mmHg = 0.097 atm

conversion used : (1 atm = 760 mmHg)

V = volume of gas = 500.0 L

T = temperature of gas = $75^oC=75+273=348K$

n = number of moles of gas = ?

R = gas constant = 0.0821 L.atm/mole.K

Now put all the given values in the ideal gas equation, we get the number of moles of gas in the container.

$(0.097atm)\times (500.0L)=n\times (0.0821L.atm/mole.K)\times (348K)$

$n=1.697mole$

Therefore, the number of moles of gas present in container are 1.697 mole.

4 0

3 years ago

Help please chapter 7.1

olga2289 [7]

1. 100N to the right
2. 10N to the left
3. 0N they are balanced
4. 0N they are balanced

8 0

3 years ago

For the skeletal chemical equation BF3(g) + NaH(s) → B2H6(g) + NaF(s) what is the coefficient of B2H6 in the balanced equation?

KonstantinChe [14]

Answer:

Coefficient in front of the $B_2H_6$ in the balanced equation - 1

Explanation:

The unbalanced Chemical equation is shown below as:-

$BF_3+NaH\rightarrow B_2H_6+NaF$

On the left hand side,

There are 1 boron atom and 3 fluorine atoms and 1 sodium and hydrogen atoms.

On the right hand side,

There are 2 boron atoms and 6 hydrogen atoms and 1 sodium and fluorine atoms.

Thus,

leftside, $BF_3$ must be multiplied by 2 to balance boron and right side, $NaF$ must be multiplied by 6 to balance fluorine. Left side, $NaH$ must be multiplied by 6 to balance sodium and hydrogen atoms.

Thus, the balanced reaction is:-

$2BF_3+6NaH\rightarrow B_2H_6+6NaF$

<u>Coefficient in front of the $B_2H_6$ in the balanced equation - 1</u>

6 0

3 years ago

Read 2 more answers

A ball is thrown in the air. The ball goes up, then changes direction and falls down. Why does the ball fall down?

Delicious77 [7]

So the acceleration has actually slowed down the ball because it was going in the direction opposite the velocity. Now see what happens as the ball falls back down to Earth. The ball has zero velocity, but the acceleration due to gravity accelerates the ball downward at a rate of –9.8 m/s2.

hope it helps

7 0

3 years ago