Chemistry Assignment: Calculations, Equations, and Reaction Prediction

This chemistry assignment solution addresses several key concepts in general chemistry. The assignment includes detailed calculations of molar mass, number of moles, and mass of various compounds. It also involves calculating the number of atoms and molecules in given samples, applying the mole concept, and using Avogadro's constant. Furthermore, the assignment requires balancing chemical equations and classifying them by reaction type. Specific examples include balancing equations for the combustion of glucose, the reaction of iron with oxygen, and the decomposition of ammonium nitrate. Additionally, students are asked to predict whether reactions will occur and write the chemical equations for those reactions, including precipitation reactions. The document concludes with a bibliography of cited sources.

Running head: CHEMISTRY
CHEMISTRY ASSIGNMENT
Name of the Student
Name of the University
Author Note

1CHEMISTRY
1.
a. Al2(SO4)3= (27 x 2)+ (32+64) x 3= 342 g/mole
b. mass= n x M (molecular mass)
or, 22.5= n x 65
or number of moles (n) of Zn= (22.5/65)= 0.34
c. Using the formula,
mass= n x M
m (mass)= 12.5 x 35= 437.5 grams (Cl2)
d. Number of atoms in CH4= 1+4= 5
Molar mass= 16
Number of moles in 0.25 g sample= (0.25/16)= 0.01
Therefore, the number of atoms= 6.023 x 1023 x 0.01 x 5= 0.3 x 1023 atoms.
e. Mass of one molecule of N2O5= 108/ (6.022 x 1023)
Mass of four molecule = 4 x 1.8 x 10-22= 7.17 x 10-22 g
f. Molar mass of C2H4= 26
or, 1 mole= 26 grams
Therefore, 9.6 grams will have= 9.6/26= 0.17 mole
g. According to Avogadros’s constant,
1 mol of an atom= 6.022 x 1023 atoms
Thus, for 22 atoms, we have= (22/6.022 x 1023)= 3.65 x 10-23 mol

2CHEMISTRY
Atomic mass of Cl= 35.
Therefore, the number of atoms= 35 x 3.65 x 10-23= 1.27 x 10-44
h. According to Avogadro,
1 mole of H2CO3 contains 6.023 x 1023 molecules.
Therefore, 3.5 moles contain= 3.5 x 6.023 x 1023 molecules
However each of the molecules contain 2 H atoms according to the formula.
Therefore, 3.5 moles will contain= 2 x 3.5 x 6.023 x 1023 atoms= 4.22 x 1047.
2. The molar mass of caffeine is 194.19 g⋅mol-1.
Moles of caffeine in a cup = 125×10−3g/194.19⋅g⋅mol-1 = 1.7 x 10-8 mol.
The above calculation gives an answer in moles. The number is
= NA⋅mol⋅×125×10−3g194.19⋅g⋅mol−1 = 6.21 x 1039
3.
a. C6H12O6 + 6O2 = 6CO2 + 6H2O
b. 4Fe + 3O2 = 2Fe2O3
c. 2NH4NO3 = 2N2 + O2 + 4H2O
d. 3SnO + 2NF3 = 3SnF2 + N2O3
4.
a. Nickel (II) chloride will react with ammonium sulfate in order to produce nickel sulfide
and ammonium chloride NH4Cl as the products.
NiCl2+ (NH4)2S = NiS + 2NH4Cl

3CHEMISTRY
b. 2AgClO4+CaBr2=2AgBr+Ca(ClO4)
The ions can recombine and form precipitate inside the solution.
c. Pb(NO3)2(aq) + Na2CrO4(aq) ---> PbCrO4(s) + 2NaNO3 (aq)
Lead nitrate= aqueous
Sodium chromate= aqueous
Lead (II) chromate= solid (precipitate)
Sodium Nitrate= aqueous
d. Zn(2+) (aq) + 2Cl(-) (aq) + 2K(+) (aq) + CO3(2-) (aq) = ZnCO3 (s) + 2K(+) (aq) + 2Cl(-)
(aq)
All the product and reactants are aqueous in nature
5. NH4+ is the ion present in the aqueous solution of salt. This is because of the fact that
ammonium is soluble and does not form a precipitate easily.

4CHEMISTRY
Bibliography
Chong, S. H., Goolamally, N., & Leong, K. E. (2019). Post-secondary Science Students'
Understanding on Mole Concept and Solution Concentration. Universal Journal of
Educational Research, 7(4), 986-1000.
Güttler, B., Rienitz, O., & Pramann, A. (2019). The Avogadro Constant for the Definition
and Realization of the Mole. Annalen der Physik, 531(5), 1800292.
Malcolm, S. A., Mavhunga, E., & Rollnick, M. (2018). A lesson on teaching the mole
concept conceptually: A learning study.
Salmi, T. O., Mikkola, J. P., & Wärnå, J. P. (2019). Chemical reaction engineering and
reactor technology. CRC Press.
Tro, N. J., Fridgen, T. D., Shaw, L., & Boikess, R. S. (2017). Chemistry: A molecular
approach. Boston, MA: Pearson.
Williamson, T., Katz, L. E., Han, J., Dobbs, H. A., Chmelka, B. F., Sant, G., & Juenger, M.
C. (2020). Relationship between aqueous chemistry and composition, structure, and
solubility of sodium aluminosilicate hydrates. Journal of the American Ceramic
Society, 103(3), 2160-2172.