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3 years ago

How many moles of Ba(NO3)2 are there in 0.25 L of a 2.00 M Ba(NO3)2 solution?

Chemistry

2 answers:

klemol [59]3 years ago

6 0

Answer:

0.5moles

Explanation:

Given parameters:

Volume of solution= 0.25L

Molarity of solution = 2.00M

Unknown:

Number of moles = ?

Solution:

To solve this problem;

Molarity is the number of moles of solute in a given volume of solution, so

Number of moles = molarity x volume

Now insert the parameters and solve;

Number of moles = 0.25 x 2 = 0.5moles

Firlakuza [10]3 years ago

3 0

Answer:

Explanation:

got it right on test

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Which of the following is NOT a cause of Earth's internal heat?

miskamm [114]

Answer:

I think it A good luck this thing is making me write 20 letters so I can give you the answer byeee

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3 years ago

To identify a diatomic gas (X2), a researcher carried out the following experiment: She weighed an empty 4.1-L bulb, then filled

kirza4 [7]

Answer:

Nitrogen, $N_2\\$

Explanation:

Hello,

This is a clear example of what the ideal gas equation is used for, thus, from its mathematical definition:

$PV=nRT$

One can spell it out in terms of mass and molar mass:

$PV=\frac{m}{M}RT$

Now, solving for the molecular mass, $M$ :

$M=\frac{mRT}{PV} =\frac{9.5g*0.082\frac{atm*L}{mol*K}*297.15K}{2.00atm*4.1L}\\ M=28.23g/mol$

Now, by taking into account that the gas is diatomic, the matching gas turns out to be nitrogen.

Best regards.

6 0

3 years ago

Read 2 more answers

A sample consisting of 1.00 mol of perfect gas molecules at 27 °C is expanded isothermally from an initial pressure of 3.00 atm

Evgesh-ka [11]

Answer:

a) reversibly

ΔU = 0

q = 2740.16 J

w = -2740.16 J

ΔH = 0

ΔS(total) = 0

ΔS(sys) =9.13 J/K

ΔS(surr) = -9.13 J/K

b) against a constant external pressure of 1.00 atm

ΔU = 0

w = -1.66 kJ

q = 1.66 kJ

ΔH = 0

ΔS(sys) = 9.13 J/K

ΔS(surr) = -5.543 J/K

ΔS(total) = 3.587 J/K

Explanation:

Step 1: Data given:

Number of moles = 1.00 mol

Temperature = 27.00 °C = 300 Kelvin

Initial pressure = 3.00 atm

Final pressure = 1.00 atm

The gas constant = 8.31 J/mol*K

(a) reversibly

Step 2: Calculate work done

For ideal gases ΔU depends only on temperature. So as it is an isothermal (T constant).

Since the temperature remains constant:

ΔU = 0

ΔU = q + w

q = -w

w = -nRT ln (Pi/Pf)

⇒ with n = the number of moles of perfect gas = 1.00 mol

⇒ with R = the gas constant = 8.314 J/mol*K

⇒ with T = the temperature = 300 Kelvin

⇒ with Pi = the initial pressure = 3.00 atm

⇒ with Pf = the final pressure = 1.00 atm

w =- 1*8.314 *300 * ln(3)

w = -2740.16 J

q = -w

q = 2740.16 J

Step 3: Calculate change in enthalpy

Since there is no change in energy, ΔH = 0

Step 4: Calculate ΔS

for an isothermal process

ΔS (total) = ΔS(sys) + ΔS(surr)

ΔS(sys) = -ΔS(surr)

ΔS(sys) = n*R*ln(pi/pf)

ΔS(sys) = 1.00 * 8.314 * ln(3)

ΔS(sys) = 9.13 J/K

ΔS(surr) = -9.13 J/K

ΔS (total) = ΔS(sys) + ΔS(surr) = 0

(b) against a constant external pressure of 1.00 atm

Step 1: Calculate the work done

w = -Pext*ΔV

w = -Pext*(Vf - Vi)

⇒ with Vf = the final volume

⇒ with Vi = the initial volume

We have to calculate the final and initial volume. We do this via the ideal gas law P*V=n*R*T

V = (n*R*T)/P

Initial volume = (n*R*T)/Pi

⇒ Vi = (1*0.08206 *300)/3

⇒ Vi = 8.206 L

Final volume = (n*R*T)/Pf

⇒ Vf = (1*0.08206 *300)/1

⇒ Vf = 24.618 L

The work done w = -Pext*(Vf - Vi)

w = -1.00* ( 24.618 - 8.206)

w = -16.412 atm*L

w = -16 .412 *(101325/1atm*L) *(1kJ/1000J)

w = -1662.9 J = -1.66 kJ

Step 2: Calculate the change in internal energy

ΔU = 0

q = -w

q = 1.66 kJ

ΔH = 0 because there is no change in energy

Step 3: Calculate ΔS

ΔS(sys) = n*R*ln(3)

ΔS(sys) = 1.00 * 8.314 * ln(3)

ΔS(sys) = 9.13 J/K

ΔS(surr) = -q/T

ΔS(surr) = -1662.9J/300K

ΔS(surr) = -5.543 J/K

ΔS(total) = ΔS(surr) +ΔS(sys) = -5.543 J/K + 9.13 J/K = 3.587 J/K

4 0

4 years ago

What is the volume in ML

BabaBlast [244]

Answer:1 mL

Explanation:

4 0

3 years ago

If 20.0 mL of Ca(OH)2 with an unknown concentration is neutralized by 37.5 mL of 0.124 M HCl, what is the concentration of the C

Nady [450]

You first need to write the balanced chemical reaction for what is going on.
Ca(OH)₂+2HCl→2H₂O+CaCl₂

After you make the balanced chemical reaction, First you find the moles of HCl used. To do this multiply 0.0375L by 0.124M to get 0.00465mol HCl. Then you multiply 0.00465mol HCl by (1mol Ca(OH)₂)/(2mol HCl) to get 0.002325mol Ca(OH)₂. Finally to find concentration of Ca(OH)₂ used you divide 0.002325mol by 0.020L to get 0.116M Ca(OH)₂.
Therefore the concentration of the unknown solution of Ca(OH)₂ was 0.116M.

I hope this helps. Let me know if anything is unclear.

6 0

3 years ago