Calculate the enthalpy of reaction for the following reaction using Hess's Law and the equations provided below.
Target Reaction: Sr(s)+C(graphite)+1 1/2 O2(g) -----> SrCO3(s) H(degrees)=?
C(Graphite)+ O2(g)-----> CO2(g) H(degrees)= -349kJ
Sr(s)+ 1/2 O2(G)-------> SrO(s) H(degrees)= -592kJ
SrO(s)+CO2(g)-------> SrCo3(s) H(degrees)= -234kJ
In: Chemistry
If 25.0 mL of a 0.238M FeO4^2- solution is allowed to react with 55.0 mL of 1.47 M aqueous ammonia, what volume of nitrogen gas can form at 25°C and 1.50 atm?
Volume = mL
In: Chemistry
Preparation of a buffer:
Dissolve in a beaker 27.3 g NaC2H3O2·3H2O in water containing 60 mL
of 1 M HCl (you need to make a 250- mL of 1 M hydrochloric acid
solution in advance by the appropriate dilution of concentrated
HCl) and dilute with the distilled water to 1 L. Invert the bottle
up to 20 times and keep the buffer in a 1 L glass bottle.
*help with dilution of concentrated hcl
In: Chemistry
Werecertainionstypicallyalwayssolubleoralwaysinsoluble?Howcouldyoutell?Includespecificexamples.
In: Chemistry
Describe in your own words how any two types of the following types of chromatography work: adsorption, partition, ion exchange, molecular exclusion, or affinity.
In: Chemistry
What volume, in liters, of O2 measured at 760 torr and 25o C is needed to completely react with 18.47 g of iron to give Fe2O3?
In: Chemistry
Describe the major properties, methods of analysis, and clinical use of:
AFP
CA-125
CEA
Beta-hCG
PSA
In: Chemistry
a. what is the difference between a flourescence excitation spectrum and a fluorescence emission spectrum?. which resembles an absorption spectrum.
b. consider a molecule that can fluoresce from the s1 state and phosphoresce from the t1state. which is emitted at longer wavelength?make a sketch showing absorption fluorescence and phosphorescence on a single spectrum.
In: Chemistry
Azulene is a beautiful blue hydrocarbon consisting of only C and H atoms. If 0.106 g of the compound is burned in oxygen, 0.364 g of CO2 and 0.0596 g of H2O are made. Determine the empirical formula of azulene from this data. [ Hint: First convert the masses of CO2 and H2O to moles, then convert the moles found to moles of C to H. ]
In: Chemistry
Provide a brief introduction/background of the molecule Oseltamivir (Tamiflu) and include a brief description of what the molecule is and how the molecule is used. Discuss how does the structure plays a role in its function and why is the shape of the molecule important to its function?
In: Chemistry
Part 1:
|
Trial |
Initial pH |
Final pH |
Final volume after titration |
Initial Buret Reading |
Total Volume Titrated |
|
#1 |
3.34 pH |
4.35 pH |
47.50 mL |
50 mL |
2.50 mL |
|
#2 |
3.39 pH |
4.20 pH |
47.90 mL |
50 mL |
2.10 mL |
|
#3 |
3.39 pH |
4.40 pH |
47.00 mL |
50 mL |
3.00 mL |
Part 2:
|
Trial |
Initial pH |
Final pH |
Final volume after titration |
Initial Buret Reading |
Total Volume Titrated |
|
#1 |
5.01 pH |
5.03 pH |
48.00 mL |
50 mL |
2.00 mL |
|
#2 |
5.01 pH |
5.04 pH |
47.00 mL |
50 mL |
3.00 mL |
|
#3 |
5.01 pH |
5.04 pH |
47.50 mL |
50 mL |
2.50 mL |
Part 3:
|
Trial |
Initial pH |
Final pH |
Final volume after titration |
Initial Buret Reading |
Total Volume Titrated |
|
#1 |
5.01 pH |
4.99 pH |
47.00 mL |
50 mL |
3.00 mL |
|
#2 |
5.01 pH |
4.98 pH |
46.80 mL |
50 mL |
3.20 mL |
|
#3 |
5.01 pH |
5.00 pH |
47.50 mL |
50 mL |
2.50 mL |
1.According to your observations, in Part 2 and Part 3, did your buret values agree with one another? If not, how would you explain the difference?
2. What conclusions can you draw when you compare Part 1 to Part 2? What about when comparing Part 1 to Part 3? Explain your reasoning.
3. Given the following, determine which set(s) correctly represents a buffer system. Explain your reasoning.
1. NaNO3
HF and KF
HCl and NaOH
HC2H3O2 and NaC2H3O2
4. What is the pH of a solution prepared by dissolving 1.00 g of Ca(OH)2 in water to make 875 mL of the solution? Show your calculations.
5. Given the following pair, determine which one is more basic. Explain your reasoning.
Photo developer with a pH of 12.0 or a solution of borax with a pH of 9.2
In: Chemistry
Chlorine gas reacts with ammonia to form nitrogen gas and ammonium chloride. If 70 g of chlorine and 50 g of ammonia form 6.2 grams of nitrogen, what is the percent yield of this reaction? What is oxidized? What is reduced?
In: Chemistry
define a buffer and give two examples of buffer solutions?
In: Chemistry
Aqueous hydrochloric acid (HCl) reacts with solid sodium hydroxide (NaOH) to produce aqueous sodium chloride (NaCl) and liquid water (H2O). If 12.9 g of sodium chloride is produced from the reaction of 19.7 g of hydrochloric acid and 40.8 g of sodium hydroxide, calculate the percent yield of sodium chloride. Round your answer to 3 significant figures.
In: Chemistry
what is the difference between chemistry and chemical
engineering ??
is it both are same ??
howmuch syllabus is same as for both ??
what exactly chemist do and what exactly chemical engineer do
??
In: Chemistry