1.) 50 protons, 68 neutrons, and 46
electrons . express your answer in chemical symbol or an Ion .
2 ).15 protons , 16 neutrons and 15 electrons . express your answer in chemical symbol or and Ion
3 .) 82 protons , 126 neutrons and 82 electrons . express your answer in chemical symbol or and Ion
In: Chemistry
100mL of ~0.1M KMnO4solution was transferred to 1000mL volumetric flask and dilute to the mark with distilled water but accidently I added 50mL more water (50 mL excessed, total 1050mL.)
0.1002g of Na2C2O4 and 32.73mL of permanganate solution were used to titrate.
please Calculate the concentration of MnO4-
In: Chemistry
1-An unknown sample does not react with Jones' reagent, does not react with Benedict's reagent, forms a precipitate when dinitrophenylhydrazine is added to it, but does not form a yellow precipitate after performing the iodoform test. The unknown is Select one:
a. Benzaldehyde
b. Ethanol
c. 3-pentanone
d. Acetone
e. Hexanal
f. Glucose
2- An unknown is either glucose or hexane. Which of these tests could you use to decide ?
a. Jones' test
b. Benedict's test
c. DNP test
d. Iodoform test
3- Which of these compounds will yield a positive test with the Jones' reagent?
Select one:
a. 3-Butanone
b. Benzaldehyde
c. 2,4-dimethylpentane
d. 2,2-dimethylpropanol
e. Benzene
4- what two impurities are most likely to be present in the asprone that you prepared? Use the results of the FeCI3 test any observed odor to help answer the question?
5- If your % yield is less than 100%, what may account for this ? Be as specific as possible. If your % yield is over 100%, what may account for this? Be as specific as possible
In: Chemistry
Determine the values of Ka and Kb for the acid base dissociation reactions and report the percent ionization for NH3 and NH4+. (this will require you to write the correctdissociation reaction for each species in water, create ice diagram and write the correct K experession for each). If you can help, that will help alot!!!!
0.1M NH4Cl: 6.53 pH, 0.1M NH4OH: 10.28 pH
0.01M NH4Cl: 9.67 pH, 0.01M NH4OH: 8.16 pH
In: Chemistry
The pH of 0.30 M solution of HCN is 5.20. Calculate the Ka value for HCN.
In: Chemistry
I'm doing a lab report determination of ascorbic acid in vitamin C tablet.
The equation used are: IO3- + 8 I- + 6 H+ <--> 3 I3- + 3 H2O
Back titration with thiosulfate: 2 S2O3-2 + I3- --> S4O62- + 3 I-
This is my value from the lab:
Mass of Na2S2O3 (g) : 7.8459 g ; Mass of KIO3 (g) : 2.5272 g
Mol of KIO3 dispensed: 0.01181 mol
Mass of tablet: 0.5986 g; mass of pulverized tablet: 0.5708 g
Volume of thiosulfate dispensed (mL): 29.9 mL
So far I calculated:
Mol thiosulfate: 0.002100 mol (not sure if its right)
Now I need to figure out how to find:
Mol of IO3- consumed by thiosulfate?
Mol of IO3- consumed by vitamin C?
Mol of ascorbic acid?
How do I find those?
In: Chemistry
If a copper acetate hydrate, Cu (C H O ) .zH O compound is found to contain 31.82% Copper, x232y2 59.14% acetate, and the remainder is water. What is the empirical formula of this compound
In: Chemistry
Portions of orbital diagrams representing the
ground-state electron configurations of certain elements are shown
here:
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Which violate the Pauli exclusion principle?
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b |
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e |
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f |
Which violate Hund's rule?
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d |
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f |
In: Chemistry
Calculate the concentration of all species in a 0.155 M solution of H2CO3.
Express your answer using two significant figures.
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| [H2CO3], [HCO−3], [CO2−3], [H3O+], [OH−] = | M |
In: Chemistry
calculate the pH of 100 mL of a buffer that is .080 M NH4Cl and .105 M NH3 before and after the addition of 1.00mL of 6.05 M HNO3
In: Chemistry
Cryolite, Na3AlF6(s), an ore used in the production of aluminum, can be synthesized using aluminum oxide. Balance the equation.
Al2O3(s) + NaOH(l) + HF(g) ---> Na3AlF6 + H2O(g)
If 11.3 kilograms of Al2O3(s), 60.4 kilograms of NaOH(l), and 60.4 kilograms of HF(g) react completely, how many kilograms of cryolite will be produced?
Which reactants will be in excess?
What is the total mass of the excess reactants left over after the reaction is complete?
In: Chemistry
A 35.00 mL solution of 0.2500 M HF is titrated with a standardized 0.1118 M solution of NaOH at 25 degrees C.
a.) What is the pH of the HF solution before titrant is added?
b.) How many mL of titrant are required to reach the equivalence point?
c.) What is the pH of 0.50 mL before the equivalence point?
d.) What is the pH at the equivalence point?
e.) What is the pH at 0.50 mL after the equivalence point?
In: Chemistry
1) What problems are involved in using sunscreens and describe what is happening internally to someone who has “the bends” and What are the two different types of asbestos and what is the difference in their effects on exposure?
In: Chemistry
what benefits or disadvantages come from using Raman spectroscopy vs gas chromatography for determining the percent alcohol in alcoholic beverages?
In: Chemistry
Select the processes that are expected to be exothermic:
| a. |
Li+(g) + F-(g) --> LiF (s) |
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| b. |
Ca2+(g) + 2e- --> Ca (g) |
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| c. |
CaBr2(s) --> Ca (s) + Br2(g) |
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| d. |
S (g) +2e- --> S2-(g) |
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| e. |
Fe (l) --> Fe (s) |
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| f. |
Fe (s) --> Fe (g) |
In: Chemistry