جامعة دمياط Chemistry Exam 21 Dec 2022 PDF

# جامعة دمياط ## Demletto University ### 21 des. 2022 ### Facity of science ### Chemistry Department ### Molecular biology students (1" Year) ### Final Exam of General Chem.I #### Pro Yassin Aggour, Prof. Elsonbaty & Dr.Neveen ## Answer the following: ### 1) - a-Define the following: Exclu...

# جامعة دمياط ## Demletto University ### 21 des. 2022 ### Facity of science ### Chemistry Department ### Molecular biology students (1" Year) ### Final Exam of General Chem.I #### Pro Yassin Aggour, Prof. Elsonbaty & Dr.Neveen ## Answer the following: ### 1) - a-Define the following: Excluded volume - Effusion of gases - Mean free path - b-Prove that real gas equation is: $$(P + \frac{a}{v²})(V - b) = RT$$ - Calculate the weight of $NaOH$ to prepare 5 l of 2M $NaOH$ (At. wt $Na = 23, H = 1, O = 16$) $Wt = MxVx\frac{MxVx}{100}$ ### 2) - a-Explain the following: Saturated solution - Osmotic pressure - ideal solution. - b-An immiscible organic liquid and water boils at $90^\circ C$, and pressure $734mmHg$. The distilled solution contains $73\%$ of organic liquid. Calculate the molecular weight of organic liquid, if you know that the vapor pressure of water at $90^\circ C$ is $526mmHg$. ## Answer the following two questions: ### 1. Draw the chemical structure of the following: - a. 2-chloropropane. - b. 1-bromobutane. - c. 3-hydroxyheptane. - d. 2-fluoro-1-pentyne. ### 2. Put true or false marks: - a. Ozonolysis of propyne, followed by reducing working up, give acetic acid. - b. The hybridization of atomic orbitals of propyne is $SP$ linear shape. - c. Trans-2-butene is more stable than cis-2-butene. **x** - d. The polarity of alkene is more than alkane. **✓** - e. The isomerization between n-butane and iso-butane is a chain isomerism type. **✓** - f. Pentane has higher boiling point than 2-methylbutane. **✓** - g. Ozonolysis of 2-butene, followed by reducing working up, give acetaldehyde. **✓** - h. The isomerization between 2-methyl-1-propanol and 2-methyl-2-propanol is a position isomerism type. **✓** ## Part III: Answer ALL the Following questions: Prof. A.Z. El-Sonbati ### 1. Choose the right answer: - The bond angle in $CH₄$ is - i. $105^\circ S$ - ii. $107^\circ S$ - iii. $109^\circ 51'$ **✓** - The bond angle in $NH₃$ is - i. $105^\circ S$ - ii. $107^\circ S$ - iii. $109^\circ 51'$ **✓** - Which of the following molecules is linear? - i. $H₂O$ - ii. $SF₂$ - iii. $BeCl₂$ **✓** - In $CH₄$, each carbon atom is - i. sp hybridized - ii. not hybridized - iii. $sp³$ hybridized **✓** - Carbon atom in $CO₂$ is: - i. $sp³$ - ii. $sp²$ - iii. $Sp$ **✓** - Classify the element as noble gases, representative elements and transition elements: $Ca₂₀, C₀₂₇, Cl₁₇, Ne₁₀, Mn₂₅$ - Name the various orbitals possible for: - i) $n=3, l=1$ - ii) $n=3, l=0$ - a- Which sets of quantum numbers are not permissible and why? - i) $n=5, l=3, m = 0, s = 1/2$ - ii) $n=3, l=2, m = 2 s = 1/2$ - iii) $n = 3, l = 2, m = 2, s = 1/2$ - iv) $n = 2, l=2, m= 0, s=-1/2$ - b- Define the following terms: i) Ionization energies ii) Atomic size Give reasons why $Ti²⁺_{22}$ has a configuration... $3s²3p 3d$ and not......$3s²3p⁴s²$ - a- An electron described by quantum numbers, $n = 5, l = 3, m = 0$ occupies: - i) 5d-orbital - ii) 5p-orbital - iii) 5f-orbital **✓** - iv) 5s-orbital - b How does the size of atoms vary from left to right in a period, and on descending a group in the periodic table? What are the reasons for these changes? - $Li₁₃ -> Be₄$ - $Na₁₀ -> Mg₁₂ -> Al₁₃$ - Why the decrease in size between $Liz$ and $Be₄$ much greater than that between $Na₁₁$ and $Mg₁₂$ or $K₁₉$ and $Ca₂₀$?