When 43.7 g g of KClO3 K C l O 3 is completely decomposed, what is the theoretical yield, in grams, of O2 ?

Express your answer with the appropriate units.

If 12.1 g of O2 is produced, what is the percent yield of O2 ?

Express your answer with the appropriate units.

Calculate the molar mass for Mn3O4 , an oxide of manganese.

Express your answer to five significant figures.

Calculate the number of moles of magnesium, chlorine, and oxygen atoms in 3.70 molesmoles of magnesium perchlorate, Mg(ClO4)2.

Express the number of moles of Mg, Cl, and O atoms numerically, separated by commas.

A sample of propane, C3H8, contains 15.0 molesmoles of carbon atoms. How many total moles of atoms does the sample contain?

Express the total number of moles of carbon and hydrogen numerically.

We will assay enzyme activity at 340 nm. The molar absorbance is higher at 260, meaning we can detect three times less cofactor. Why don’t we use that wavelength? If you had to pick the worst possible wavelength to monitor, what would it be more context: doing assays after purifying proteins from animal tissue. Testing for enzymatic activity

a. What is the pH of the buffer prepared by mixing 250. mL of 0.200 M benzoic acid and 100. mL of 0.250M NaOH? pKa=4.19

b. A buffer containing 1.00 M concentrations of HOAc and NaOAc has a pH of 4.742. (a) What is the pH of the soln’ after 0.0100 mol of HCl has been added to 1.00 L of the buffer? (b) What is the pH of the soln’ after the addition of 0.0100 mol of NaOH? (c) What is the buffer capacity and pH change for each soln’ [ in (a) and (b)]?

If the atmospheric burden of CO₂ increases by 18.0 Gt (gigatonnes, 1Gt= 1 x 10¹² kg) over a given period of time, starting now, and the current atmospheric CO₂ is 408.3 ppm, what will the concentration of CO₂ be (in ppm) after this increase? (Assume a total atmospheric mass of 5.10 x 10²¹ g and an average molar mass for air of 29.0 g/mol)

. Suppose that you are preparing CaCl2 solutions.

a. What mass of CaCl2(s) would you need to add to make 100.0 mL of a 0.020 M solution?

b. If you actually added 0.228 g of CaCl2(s), what would the solution concentration be?

c. You dilute this solution 5-fold, adding 10.00 mL into a 50.00 mL volumetric flask. What is the resultant concentration?

1. why does olive oil have a lower melting point than butter fat?

2. how does LDL differ from HDL's

3. In a helix, how does bond occur between the amino acids in the peptide bond?

4. what is the difference in bonding between an alpha helix and a Beta plated sheet?

5. if serine were replaced by valine in a protein how would the tertiary stucture be affected?

6.(a) How does an enzyme speed up the reaction of a substrate

(b) after the products have formed what happens to the enzymes?

7. How does a lactase make the reaction go faster.

A chemist titrates 30.0 mL of 0.840 M hydroxylamine, HONH2 Kb = 1.1 x 10–8 , with 0.900 M HNO3. Calculate the pH at each of the following volumes of added titrant.

12.0 mL HNO3

14.0 mL HNO3

28.0 mL HNO3

35.0 mL HNO3

what is the relationship between volatility and the vapor pressure of a solvent

We’re going to titrate formic acid with the strong base, NaOH. There is initially 100. mL of 0.50 M formic acid and the concentration of NaOH is 1.0 M.

A. What is the initial pH of the formic acid solution?

B. What is the percent ionization under initial conditions?

C. After the addition of 10 mL of NaOH, what is the pH?

D. After the addition of 25 mL of NaOH, what is the pH? Think about where in the titration this brings you.

E. What volume of NaOH is required to reach the equivalence point?

F. What is the pH at the equivalence point?

G. What is the pOH at the equivalence point?

H. If, instead of NaOH being added, 0.05 moles of HCl is added by bubbling the gas through the solution. Assume that the volume has not changed. What is the percent dissociation of formic acid?

Sorry! i know its alot

How to make solutions

Choose the correct formula from above. Please show all the steps and be sure to clearly show what values are being using relating to the formula.

1. Calculate the amount of 0.01M KMnO₄ solution and the amount of dH₂O needed to make 10 ml each of the following solutions:

Parallel Dilution Technique

1) Each molecule of testosterone contains 19 atoms of carbon (plus other atom). The mass percent of carbon in testosterone is 79.12%. What is the molar mass of testosterone?

2) A substance contains 23.0g of sodium, 27.0 g aluminum and 114.0 g fluorine. How many grams of sodium are there in a 159 g sample of the substance?

Industrial chemists make hydrofluoric acid (which is used in aluminum and uranium processing, to etch glass, and to make CFCs) from the reactions of aqueous calcium fluoride and aqueous sulfuric acid. Write the complete equation for this reaction. (Use the lowest possible coefficients. Include states-of-matter in your answer.)

chemPad

Help

Constants

Heat of fusion (?Hfus) is used for calculations involving a phase change between solid and liquid, with no temperature change. For H2O, ?Hfus=6.02 kJ/mol.

Specific heat capacity (C) is used for calculations that involve a temperature change, but no phase change. For liquid water, C=4.184 J/(g??C).

Heat of vaporization (?Hvap) is used for calculations involving a phase change between liquid and gas, with no temperature change. For H2O, ?Hvap=40.7 kJ/mol.

Part B

How much heat is required to raise the temperature of 92.0g of water from its melting point to its boiling point?

Express your answer numerically in kilojoules.

A student collected the following data as part of the Determination of KClOx:

Temperature: 23.0 oC

Atmospheric Pressure: 749.3 torr

PH2O: 21.454 torr

Volume of O2: 89 mL

Mass of KClOx: 0.372 g

a. Determine the moles of O2 collected and the moles of monoatomic oxygen, O.

b. Determine the mass of O2 and of KCl at the end of the reaction.

c. Determine the mole ratio of O to KCl and provide the formula for the unknown