Boyle's Law Problems..?

I need help on some questions for chemistry please.

1.A sample of 100.0 mL of oxygen has a pressure of 10.50 kPa. The pressure is then changed to 9.91 kPa. Assume that temperature remains constant,

a.predict whether the volume will increase or decrease.

b.What is the new volume of the gas?

2.A flask containing 95.0cm^3 of hydrogen was collected at a presure of 731 mm of mercury. At what pressure would the volume of hydrogen be 70.0cm^3? Assume that temperature reamins constant.

a.Predict whether the pressure will increase or decrease.

b.What is the pressure of the gas at 70cm^3?

3.A gas a volume pf 50.0m^3. Assuming that temperature remains constant, what volume would the gas occupy

a.if the pressure is doubled?

b.if the pressure is cut in half?

c.if the pressure is tripled?

4.A scuba diver inflates a balloon to 0.25ft^3 at a depth of 99ft (where the pressure is about 4 atm) Assume that temperature remains constant. its ascent, will the balloon increase or decrease in volume?

b.what will the volume of the balloon be at the surface (1.0 atm)?


5.A gas is confined in a cylinder with a movable piston at one end. When the volume of the cylinder is 760.0 cm^3, the pressure of the gas is 125.0 kPa. When the cylinder volume is reduced to 450.0cm^3, what is the pressure in kPa? Assume that temperature remains constant.

2 Answers

  • Dr.A
    Lv 7
    1 decade ago
    Favorite Answer

    Boyle's law : p1V1 = p2V2


    the pressure decreases and the volume will increase

    100.0 x 10.50 = V x 9.91

    V = 106.0 mL


    the volume decreases and the pressure will increase

    95.0 x 731 = 70.0 x p

    p = 992 mm Hg


    let initial pressure = p


    50.0 p = V x 2p

    V = 50.0 p / 2p = 50.0 /2 = 25.0 m^3


    50.0 p = V x p/2

    100 p = V x p

    V = 100 m^3


    50.0 p = V x 3p

    V = 50.0 p / 3p = 50.0 /3 =16.7 m^3


    in its ascent the pressure decreases and the volume will increase

    0.25 x 4 = V x 1.0

    V = 1.0 ft^3


    760.0 x 125.0 = 450 p

    p = 211.1 kPa

  • Anonymous
    1 decade ago

    1. given

    Volume 1= 100.0 mL

    pressure 1= 10.50kPa

    Pressure 2= 9.91kPa


    Volume 2

    using boyles law formula P1V1 = P2V2

    we can aquire the new volume of gas using the new formula and by answering you can say wheter the volume increases or decreases

    V2= (P2)(V1)/(P1)

    now you substitute and answer

    2. volume1 = 95.0 cm^3

    Pressure1 = 731 mmHg

    Volume 2= 70.0 cm^3


    pressure 2

    again. P1V1 = P2V2

    P2= (P1)(V2)/(V1)

    subtitute the values and you can get the answer from your questions

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