Consider the reaction A -> products at 312 K.

For this reaction it was observed that the first three half lives were 10.7 h, 5.35 h, and 2.675 h when [A] 2.873M. How long will it take for [A] to decrease by 47%?

Time for [A] to decrease by 47% (in hours) = Anwser is 10.1h need help on how to get this anwser.

15) Name two materials that are theoretically strong enough to build a space elevator.?

Please explain in clear words. Thanks

Starting from the first and second law of thermodynamics, derive the fundamental equation for A in its natural variables. a) Derive the Maxwell relation that s related to this equation. b) Show that for df= gdx + hdy we have an exact equation if:

Without doing detailed calculations, indicate which of the following electron transitions in the hydrogen atom results in the emission of light of the longest wavelength. Explain why.

a. from n = 1 to n = 2

b. from n = 4 to n = 3

c. from n = 1 to n = 6

d. from n = 3 to n = 2

Consider the titration of 100.0 mL of 0.016 M HOCl (Ka=3.5×10?8) with 0.0400 M NaOH.

1) How many milliliters of 0.0400 M NaOH are required to reach the equivalence point?

2) Calculate the pH after the addition of 10.0 mL of 0.0400 M NaOH.

3) Calculate the pH halfway to the equivalence point .

4) Calculate the pH at the equivalence point.

thank you!

The law of mass conservation is another fundamental law in chemistry. this law states that matter can neither be created or destroyed, which means that in a chemical reactions where all the reactant is converted into product, the mass of reactant must be equaly equal to mass of product produced. A) consider 2 precipitation reactions B) experimental procedure that you can use in lab C) contemplate how you might visually represent this data (I) what variables might you need to plot (ii) how would your choice of graph illistrate the law of mass conservation

How many grams of dipotassium succinate trihydrate (K2C4H4O4·3H2O, MW = 248.32 g/mol) must be added to 800.0 mL of a 0.0417 M succinic acid solution to produce a pH of 5.974? Succinic acid has pKa values of 4.207 (pKa1) and 5.636 (pKa2).

You are fractionally distilling 100 mL of a 1:1 solution of cyclohexane and toluene. After 2 mL has distilled you collect a sample for analysis. It is determined that your sample contains a mixture that is 92:8 cyclohexane/toluene. Calculate the number of theoretical plates if the relative volatility (?) of the original solution is 2.33

Write a balanced reaction that describes the conversion of Spessartine (Mn3Al2Si3O12) to Tephroite (Mn2SiO4), Kyanite (Al2SiO5), and Quartz (SiO2)

Please show work and explain.

Please show the mechanism of RCHO or a ketone reacting with a nucleophile.

A compound dissolved in methanol and need to remove by distillation because heat is sensitive, a person hesitate to rait temp above 0C and instead decide to use vacuum distillaion. What required pressure for pure methanol to boil at this temp?

Pure phosgene gas (COCl₂), 0.0340 mol, was placed in a 1.30-L container. t was heated t o730.0 K, and at equilibrium, the pressure of CO was found to be 0.513 atm. Calculate the equilibrium constant K_p for the reaaction:

CO(g) + Cl₂(g) >< COCl₂(g)

The equilibrium constant  for the reaction CCl4(g) = C(s) + 2Cl2(g)

at 700ºC is 0.85. Determine the initial pressure of carbon tetrachloride that will produce a total equilibrium pressure of 2.30 atm at 700ºC.

10.00mL of 1.000M HA (a weak acid) was mixed with 5.00mL of 0.500M NaOH. Then the mixture was diluted to 50.0.mL with distilled water. The pH of the solution read 5.00.

1) What is the chemical equation between HA and NaOH.

2) Calculate moles of each. What is the limiting reactant?

3) Calculate the moles of each left at the end of this reaction. Calculate the Molarities for each. (What is the total volume?)

4) Write a balanced equation for dissociation of HA(aq) in water.

5) Write an expression for K for the equation above.

6) Draw the appropriate ICE table. Fill in all the information.

Hint : Calculate [H3O+] at equilibrium from pH.

7) Calculate K.

8) What is the difference between K and Ka? Is the K from question above Ka? Explain.