CH4(g) + Cl2(g)  CH2Cl2(g) + 2 HCl(g) Use the data in the table below to calculate the standard enthalpy, ∆H˚, for the reaction above. Substance CH4(g) CH2Cl2(g) HCl(g) ∆Hf˚, kJ•mol-1 –74.6 –95.4 –92.3

A 0.01 % solution of paracetamol API was analysed by HPLC giving a peak at 4.35 minutes from a c18 5 micron column. The peak area is 159785643. The peak area of a 0.05 % paracetamol standard is 80045687. Calculate the % assay for paracetamol API. Do you think this would comply with release specification of an active drug substance?

Ammonia rapidly reacts with hydrogen chloride, making ammonium chloride. Calculate the number of grams of excess reactant when 6.16 g of NH₃ reacts with 4.46 g of HCl

What do you think would happen if you connected the pencil lead connected to the negative post after being in the copper nitrate solution to the positive post of the battery? explain why you think there would or would not be an observable change.

5. Using boxes to represent orbitals, draw the molecular orbital energy level diagrams for the following molecules, with energy increasing vertically, putting electrons into the appropriate orbitals. For each indicate: the bond order and whether the molecule is paramagnetic or diamagnetic.

a) B₂

b) CN-

c) NO

d) NO+

You may want to reference (Pages 821 - 825) Section 17.8 while completing this problem. You mix a 120.0 −mL − m L sample of a solution that is 0.0123 M M in NiCl2 N i C l 2 with a 185.0 −mL − m L sample of a solution that is 0.300 M M in NH3 N H 3 .

After the solution reaches equilibrium, what concentration of Ni2+(aq)Ni2+(aq) remains? The value of KfKf for Ni(NH3)62+Ni(NH3)62+ is 2.0×1082.0×108.

Express the concentration to two significant figures and include the appropriate units.

Why does the formation of 5-methylcytosine look more chemically difficult than formation of N6-methyladenine?

Calculate the pH for each of the following cases in the titration of 50.0 mL of 0.220 M HClO(aq) with 0.220 M KOH(aq). The ionization constant for HClO is 4.0e-8.

(a) before addition of any KOH

(b) after addition of 25.0 mL of KOH

(c) after addition of 30.0 mL of KOH

(d) after addition of 50.0 mL of KOH

(e) after addition of 60.0 mL of KOH

A gaseous mixture contains 413.0 Torr of H2(g), 391.5 Torr of N2(g), and 65.7 Torr of Ar(g). Calculate the mole fraction, X, of each of these gases.

Calculate the equilibrium ¹³⁵I concentration and the equilibrium ¹³⁵Xe for 3.0 w/o enriched fuel in a reactor that operates with a thermal neutron flux of 1 x 10¹³/(cm²*s). Use the value of Σ_f = 3.

Please explain your work!

An aqueous sodium sulfide solution has a vapor pressure of 80.9mmHg at 50 ?C. The vapor pressure of pure water at this temperature is 92.6 mmHg. (Assume sodium sulfide completely dissociates.)

What is the concentration of sodium sulfide in mass percent?

Please show all work.

. The freezing point of benzene is 5.5^oC What is the freezing point of a solution of 5.00 g C₁₀H₈ in 444 g   of benzene. You will need to look up the freezing point depression constant for benzene in a reference book.                 Calculated FP:

Benzene K_f = ___________ *remember you will need “m”, which is in Kg     Name of reference used: __________________      

Calculated FP:    

i factor used and explain i factor:

1)Write the complete equation (balanced with states) for the reaction between potassium chloride and lead (II) nitrate?

2) Which precipitate forms in the above mentioned reaction?

3) You mix 16.00 mL of 0.778 M lead (II) nitrate with 18.00 mL of 0.813 M potassium chloride, and collect and dry the precipitate. Calculate the following:

a) Moles of lead (II) nitrate used:

b)Moles of potassium chloride used:

c) Moles of precipitate expected from lead (II) nitrate:

d) Moles of precipitate expected from potassium chloride:

e) Compare parts c and d to indicate the limiting reactant.

f) What mass of precipitate do you expect to obtain from this reaction?

g) If the actual yield of the precipitate you recover is 0.916g, what is the percent yield of the precipitate?

show work please

Liquid A has a normal boiling point of 64 deg C and liquid B has a normal boiling point of 98 deg C. a) which has the greater vapor pressure? b) which has the weaker intermolecular attractive forces in the liquid state?