Why was Cu prepared from a pure metal? Why was Ca prepared from a salt? Why is CaCO₃ a better salt for this purpose than CaCl₂?

an unkown hydrocarbon contain carbon hydrogen and oxygen combustion of 1.6 g of the hydrocarbon produces 1.0286 g h2o and 3.7681 g co2. what is the empiral formula of this compound?

Urea,NH2CONH2, is manufactured from ammonia and carbon dioxide according to the following equation: 2 NH3(g) +CO2 (g) ->NH2CONH2 (aq)+H2O (l)

What volume of ammonia gas at 25 o C and 1.5 atm is needed to make 1500g of urea?

Please explain!

A solution containing 87.32g of dissolved mercury (III) nitrate is mixed with a solution containing 34.62g of dissolved sodium sulfate. A chemical reaction occurs, and a precipitate is produced. How many grams of solid are produced from the reaction and how many grams of excess reactant remain after the reaction is complete?

As a sample of what you know about equilibrium, select THREE items from this list and discuss how each of them pertains to equilibrium: Colligative properties, Free Energy, Batteries, Temperature, pH.

Use the equation 6KI + SHNO3 ----> 6KNO3 + 2NO + 3I2 + 4H2O. Note that 1 mole of any gas is measured at STP will occupy 22.4L.

a.) If 38g of KI are reacted, what mass of KNO3 will form?

b.) What volume of NO gas, measured at STP, will produced if 37.0g of HNO3 are consumed?

c.) If 0.50 mole of KI is to be reacted, what volume (in mL) of 6.00 M HNO3 will be required?

d.) When the reaction produces 6.0 moles of NO, how many molecules of I2 will be produced?

e.) How many grams of molecular iodine can be obtained by reacting 45.0mL of a 0.350 M KI solution?

5.00 moles of N₂ and 8.00 moles of H₂ are placed in an empty container, the container is heated to 887 degrees Celsius, and a catalyst is added that catalyzes the rxn. of these gases to form NH₃ as the only product. At equilibrium 1.00 mole of NH₃ is found to be present. Find number of moles N₂ and moles H₂ present at equilibrium.

* I think that the concentrations of the reactants changes by 1 mole but I'm not enitrely sure if that is correct.

2) You have 25 ml of an ATP solution. You take 30 µl and dilute to a final volume of 10 ml. The absorbance of this solution is 0.432. What is the concentration of the undiluted ATP solution? (molar extinction coefficient = 15,400 M-1cm-1).

If you could upload image the solution you worked out on paper, that would be preferred.

1.What is the molality of a solution consisting of 1.34 mL of CCl₄ (D=1.59 g/mL) in 65.0 mL of CH₂Cl₂ (D=1.33 g/mL).

2. Calculate the molarity of 3.58 m aqueous RbCl solution with a density of 1.12 g/mL.

3.An acidic solution containing 571.4g H₂SO₄ per liter has a density of 1.329 g/mL. Calculate the molality of H₂SO₄ in this solution.

A surface water sample of 50 ml was taken to determine the concentration of an organic pollutant in the sample. An organic solvent was used as extracting solvent. On analysis of both phases by GC-MS, the pollutant concentration (mass/vol based) in the organic phase was 5 times that found in the aqueous phase. If after the second extraction (each using 50ml fresh organic solvent) the concentration of pollutant in the organic phase was 18 ppm (mass basis), determine the initial mass of pollutant in the water sample before any extractions were carried out. The density of solvent used is 0.65 g/ml & of water is 1.0 g/ml.

Question 1.

An environmental scientist isolates a pollutant (compound X) from a factory’s effluent stream and dissolves it in water. Experiments are then conducted using liquid – liquid extraction to optimize its extraction. Using diethyl ether as the extracting phase, the following distribution ratios, D, are calculated as a function of pH:

1. Does compound X appear to have acidic functional groups, basic functional groups or both types of groups? Explain your answer.
2. The distribution coefficient, K_D, at pH 12 is 76.3. Calculate the K_a value for compound X.
3. The scientist performed multiple extractions of the pollutant from 10 mL of water at pH 6 using a total volume of diethyl ether of 100 mL. What mass of compound X will remain in the aqueous phase after 4 consecutive   extractions if the initial concentration of the pollutant was 0.1 M.

(Note: molar mass of compound X = 76 g/mol)

State the theory and explain how NMR and IR spectroscopy work.

Mass of aspirin: 0.3839

Maximum amount (g) of aspirin possible if salicylic acid is the Limiting Reagent: ?

Maximum amount (g) of aspirin possible if acetic anhydride is the Limiting Reagent: ?

Maximum amount (g) of aspirin possible (the Theoretical Yield): ?

Percent Yield (%) of Aspirin: ?

What are the differences between polyamides and proteins ? I) Polyamides are unable to undergo hydrogen bonding between individual polymer chains. II) Polyamides usually do not have hydroxyl- or thiol-groups as side chains. III) Proteins and polyamides can be partially crystalline. IV) Polyamides have a more stable bond between their monomers than proteins have between the individual amino acids.

Choose one answer.

A. I and II
B. II and III are correct
C. II and IV
D. III and IV