Full Name: _______________________________________________
Final Exam (Online) Time: 4 hr. Total Marks: 20
Note: Read each question carefully, answer the questions by showing all your calculations in the space provided. PARTIAL CREDIT WILL BE GIVEN. IF NO WORK IS SHOWN YOU WILL GET NO CREDIT.
- Ammonia burns in oxygen to form nitric oxide (NO) and water vapor. How many volumes of NO are obtained from one volume of ammonia at the same temperature and pressure?
b) What is the volume (in liters) occupied by 49.8 g of HCl at STP?
Q2. (2.0 Points)
- Prove PV = nRT with the help of Gas laws
- Show that “sum of the mole fractions is unity (1)”
Q3. a) How much heat is given off when Mercury 800 g cools from 5 0C to 4 0C? (2.0 Points)
Specific heat for Hg=o.139 J/g. 0C
b) Calculate the milliliters of 0.75 M HCl required to neutralized completely 25.0 ml of 0.15 M Ba(OH)2
Q4. Q.2. Consider the SO2 molecule: (2.0 Points)
a) Draw the Lewis structure of this molecule.
b) What is its electron domain geometry?
c) What is its molecular geometry?
d) What is the hybridization around the central atom?
Q5. Determine the oxidation number for the indicated elements in each of the following substances: (2.0 Points)
- Br in HBrO2 b) C in C2O42-
c) C in COCl2 d) P in H2PO4–
Q.6 Calculate the wavelength in (nm) of a photon emitted by a hydrogen atom when its electron drops from the n=5 state to the n=3 state. (2.0 Points)
Q.7 Complete the following Table ( 2.0 Points)
cobalt (II) chloride
Lead (IV) sulfide
Q8. Element X has two natural isotopes: X-63 (62.940 amu) and X-65 (64.928 amu). Calculate the atomic mass of element X given the abundance of X-63 is 69.17%. (2.0 Points)
Q9. What is the volume of a sample of fool’s gold that displaces the water level from 25.5 mL to 35.0 mL in a graduated cylinder? (2.0 Points)
Q10. Read each question carefully, decide which is the correct answer? (2.0 Points)
a) How many significant digits are there in 0.1941205
b) If a rectangular Al block measures 3.80 cm by 2.55 cm by 1.25 cm. What is the volume of the rectangular solid?
A. 12.1 cm3
B. 1.19 cm3
C. 1.86 cm3
D. 7.75 cm3
c) Round off the following measurement to 3 significant digits: 738.8 mL
A. 740 mL
B. 738 mL
C. 739 mL
D. 7260 m
d) How many neutrons are in the nucleus of an atom of copper 65?
- None of the above
e) Which of the following colors of light has the highest energy?
- None of the above