The most abundant isotope of strontium, Sr-88, contains thirty-eight protons and fifty neutrons and has a mass of 87.9056 u.

a)What is the mass defect for this nucleus in atomic mass units? In kilograms? atomic mass units u

b) kilograms kg

Determine the purity of an Aluminum can. In words how would you determine the purity? Also, make up random numbers to calculate how to find the purity of an Aluminum can.

1) Fill in columns 1-7 of the table

Three major spectroscopic methods for elemental analysis atoms are Atomic Absorption Spectroscopy, Atomic Emission Spectroscopy, and Atomic Mass Spectroscopy. Describe 3-4 major parts of the experimental setup for each of the three methods.

Determine the pH of a solution when 26.6 mL of 0.029 M HNO3 is mixed with 16.7 mL of....

A) 0.0120 M NaOH. D) 0.144 M KOH

B) distilled water

C) 0.0060 M HCl

The enthalpy change is -400 kJ for reaction: 2 Al(s)+ 3/2 O2(g) ? Al2O3(s). What is the ?H for the following reaction? 2 Al2O3(s) ? 4Al(s) + O2(g) is

Calculate E_cell for the following electrochemical cell:

Pt/Fe²⁺ (0.0725M), Fe³⁺ (0.110M)// MnO4^- (0.0822M), H⁺ (1.00M), Mn²⁺ (0.0205M) /Pt

Redox Reactions

1) What distinguishes a redox reaction from a chemical reaction such as a double replacement?

2) COnsider the following unbalanced net ionic redox equation.

VO₂⁺+SO₃^2- -> VO⁺+SO₄^2-

a) Name the oxidizing agent in this reaction.

b) Name the ion that is oxidized in this reaction.

c) Balance this net ionic redox equation in acidic solution.

± Enthalpy of Reaction: State and Stoichiometry

Use the data below to answer the questions.

Keep in mind that the enthalpy of formation of an element in its standard state is zero

Part D

Suppose that 0.290 mol of methane, CH4(g), is reacted with 0.440 mol of fluorine, F2(g), forming CF4(g) and HF(g) as sole products. Assuming that the reaction occurs at constant pressure, how much heat is released?

Express your answer to three significant figures and include the appropriate units

Determine the pH of an HNO2 solution of each concentration. In which cases can you not make the simplifying assumption that x is small?

a. 0.250 M
b. 0.0500 M
c. 0.0250 M

How many grams of solid ammonium bromide should be added to 1.50 L of a 0.118 M ammonia solution to prepare a buffer with a pH of 9.930 ? grams ammonium bromide = ? g

How many grams of solid ammonium chloride should be added to 1.00 L of a 0.291 M ammonia solution to prepare a buffer with a pH of 8.340 ?
grams ammonium chloride =? g

What is the purpose of rinsing platinum electrodes with acetone or ethyl alcohol?

Use standard enthalpies of formation to calculate ΔH∘rxn for the following reaction: SO2(g)+12O2(g)→SO3(g) : C(s)+H2O(g)→CO(g)+H2(g) : N2O4(g)+4H2(g)→N2(g)+4H2O(g)

These are reactions I did in my lab. I need to write the molecular, total ionic, and net ionic reactions for them. Even after watching Khan Academy and using my book, I was still unsure, so I asked the professor and he said every single one was wrong and told me to figure it out.

I know this is long, but I would really appreciate it. I need the molecular, total ionic, and net ionic equations for all of them. It's not making sense to me. Thank you.

a. HCl + CaCO₃ ­ → HCO₃ + CaCl₂

b. NaOH + HCl → NaCl + H₂O

c. NaOH + NH₄Cl → NaCl + NH₄OH

d. FeCl₃ + NaOH → NaCl + Fe(OH)₂

e. CoCl₂ + FeCl3 → NR

f. AgNO₃ + CoCl₂ → AgCl + Co(NO₃)₂

g. Na₂CO₃ + AgNO₃ → NaNO₃ + Ag₂CO₃

h. CuSO₄ + Na₂CO₃ → CuCO₃ + NaSO₄

i. CuSO₄ + BaCl₂ → CuCl + BaSO₄

j. NaSO₄ + CuSO₄ → NR

k. NiCl₂ + Na₃PO₄ → NiPO₄ + NaCl

For the reaction 2Co3+(aq)+2Cl−(aq)→2Co2+(aq)+Cl2(g). E∘=0.483 V what is the cell potential at 25 ∘C if the concentrations are [Co3+]= 0.456 M , [Co2+]= 0.451 M , and [Cl−]= 4.50×10−2 M and the pressure of Cl2 is PCl2= 2.30 atm ?