Skip to main content
Chemistry LibreTexts

8.4: Unit 8 Practice Problems

  • Page ID
    260668
  • \( \newcommand{\vecs}[1]{\overset { \scriptstyle \rightharpoonup} {\mathbf{#1}} } \)

    \( \newcommand{\vecd}[1]{\overset{-\!-\!\rightharpoonup}{\vphantom{a}\smash {#1}}} \)

    \( \newcommand{\id}{\mathrm{id}}\) \( \newcommand{\Span}{\mathrm{span}}\)

    ( \newcommand{\kernel}{\mathrm{null}\,}\) \( \newcommand{\range}{\mathrm{range}\,}\)

    \( \newcommand{\RealPart}{\mathrm{Re}}\) \( \newcommand{\ImaginaryPart}{\mathrm{Im}}\)

    \( \newcommand{\Argument}{\mathrm{Arg}}\) \( \newcommand{\norm}[1]{\| #1 \|}\)

    \( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\)

    \( \newcommand{\Span}{\mathrm{span}}\)

    \( \newcommand{\id}{\mathrm{id}}\)

    \( \newcommand{\Span}{\mathrm{span}}\)

    \( \newcommand{\kernel}{\mathrm{null}\,}\)

    \( \newcommand{\range}{\mathrm{range}\,}\)

    \( \newcommand{\RealPart}{\mathrm{Re}}\)

    \( \newcommand{\ImaginaryPart}{\mathrm{Im}}\)

    \( \newcommand{\Argument}{\mathrm{Arg}}\)

    \( \newcommand{\norm}[1]{\| #1 \|}\)

    \( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\)

    \( \newcommand{\Span}{\mathrm{span}}\) \( \newcommand{\AA}{\unicode[.8,0]{x212B}}\)

    \( \newcommand{\vectorA}[1]{\vec{#1}}      % arrow\)

    \( \newcommand{\vectorAt}[1]{\vec{\text{#1}}}      % arrow\)

    \( \newcommand{\vectorB}[1]{\overset { \scriptstyle \rightharpoonup} {\mathbf{#1}} } \)

    \( \newcommand{\vectorC}[1]{\textbf{#1}} \)

    \( \newcommand{\vectorD}[1]{\overrightarrow{#1}} \)

    \( \newcommand{\vectorDt}[1]{\overrightarrow{\text{#1}}} \)

    \( \newcommand{\vectE}[1]{\overset{-\!-\!\rightharpoonup}{\vphantom{a}\smash{\mathbf {#1}}}} \)

    \( \newcommand{\vecs}[1]{\overset { \scriptstyle \rightharpoonup} {\mathbf{#1}} } \)

    \( \newcommand{\vecd}[1]{\overset{-\!-\!\rightharpoonup}{\vphantom{a}\smash {#1}}} \)

    Question 1. 

    If the pressure inside a tank is 100. psi, what is this pressure in kPa, mPa, atm, mmHg?

    Answer
    \[\mathrm{100\: \cancel{psi.} \times \dfrac{101\: kPa}{14.7\:\cancel{psi.}}=687\: kPa}\]      \[\mathrm{100\: \cancel{psi.} \times \dfrac{0.101\: MPa}{14.7\:\cancel{psi.}}=0.687\: MPa}\]     \[\mathrm{100\: \cancel{psi.} \times \dfrac{1\: atm}{14.7\:\cancel{psi.}}=6.8\: atm}\]    \[\mathrm{100\: \cancel{psi.} \times \dfrac{760\: mmHg}{14.7\:\cancel{psi.}}=5170\: mmHg}\]

    Question 2. 

    A gas occupies a volume of 17.4L at 11.2 psi, what will it's volume be if the pressure is increased to 13.6psi and the temperature is held constant?

    Answer
    P1V1 = P2V2    (11.2psi)(17.4L) = (13.6psi)(V2 )       V2 = 14.3L

    Question 3.

    A gas has a volume of 186mL at 32°C, what will it's volume be if the temperature of the gas is increased to 104°C and the pressure is held constant?

    Answer
    V1/T1 = V2/T2  Remember that when using gas laws, temperature should always be in K.  (186mL) / (305K)  = (V2) / (377K)        V= 230mL

    Question 4. 

    A container of neon at a pressure of 550mmHg and a temp of 120°C is heated (at a constant volume) until the temperature is 360°C.  What is the new pressure of the heated neon?

    Answer 

    P1/T1 = P2/T2  Remember that when using gas laws, temperature should always be in K.  (550mmHg) / (393K)  = (P2) / (633K)        P= 890 mmHg

    Question 5. 

    A cylinder containing 12.0L of compressed air at 23.0atm and -20.0°C is opened and the air escapes into a room which has a pressure of 0.960atm and warms to 28.0°C, what is the final volume of the air from the cylinder?

    Answer

    clipboard_e7784f146962c7437360b0c2b7e044f5c.png

     Question 6. 

    If a gas has a volume of 19.8L at standard temperature and pressure (STP),  how many moles of gas are there?

    Answer

    clipboard_e60f6ea233886169aecc1a2c3ed3bf9ca.png

    Question 7.  

    If 1.0 grams of a gas occupies a volume of 330mL at STP, what is the molecular weight of the gas?

    Answer

     clipboard_e7bb5d398b1423f0300f10fad6382077e.png

    Question 9.  

    A gas occupies 6.4L at 102kPa and 294K, what will the temperature of the gas be at 8.7L and 97kPa?  

    Answer

    clipboard_ebe9b06c878bf0a18ae7815bd905c58dc.png

    Question 10. 

    If I have 2.6 moles of a gas at a pressure of 4.3 atm and a volume of 8.4 liters, what is the temperature? (R=0.0821 L*atm/mol*K)

    Answer

    clipboard_ea9a12bc5e325b4e4c97a1079d9ddfb11.png


    8.4: Unit 8 Practice Problems is shared under a not declared license and was authored, remixed, and/or curated by LibreTexts.

    • Was this article helpful?