Harun Al-Rashid Abbasid Caliph Profile

Harun Al-Rashid Abbasid Caliph Profile Harun Al-Rashid Was Also Known As Haroun ar-Rashid, Harun al-Raschid or Haroon al Rasheed Harun Al-Rashid Was Known For Creating a fabulous court at Baghdad that would be immortalized in The Thousand and One Nights. Harun al-Rashid was the fifth Abbasid caliph. Occupations Caliph Places of Residence and Influence Asia: Arabia Important Dates Became caliph: Sept. 14, 786 Died: March 24, 809 About Harun al-Rashid Born to the caliph al-Mahdi and the former slave-girl al-Khayzuran, Harun was raised at court and received the bulk of his education from Yahya the Barmakid, who was a loyal supporter of Haruns mother. Before he was out of his teens, Harun was made the nominal leader of several expeditions against the Eastern Roman Empire; his success (or, more accurately, the success of his generals) resulted in his earning the title al-Rashid, which means the one following the right path or upright or just. He was also appointed governor of Armenia, Azerbaijan, Egypt, Syria and Tunisia, which Yahya administered for him, and named second in line to the throne (after his older brother, al-Hadi). Al-Mahdi died in 785 and al-Hadi died mysteriously in 786 (it was rumored that al-Khayzuran arranged his death), and Harun became caliph in September of that year. He appointed as his vizier Yahya, who installed a cadre of Barmakids as administrators. Al-Khayzuran had considerable influence over her son until her death in 803, and the Barmakids effectively ran the empire for Harun. Regional dynasties were given semi-autonomous status in return for considerable annual payments, which enriched Harun financially but weakened the power of the caliphs. He also divided his empire between his sons al-Amin and al-Mamun, who would go to war after Haruns death. Harun was a great patron of art and learning, and is best known for the unsurpassed splendor of his court and lifestyle. Some of the stories, perhaps the earliest, of The Thousand and One Nights were inspired by the glittering Baghdad court, and King Shahryar (whose wife, Scheherazade, tells the tales) may have been based on Harun himself. More Harun al-Rashid Resources Iraq: Historical Setting Encyclopedia article on Abbasids Harun al-Rashid on the Web Harun al-RashidInformative collection of data at NNDB. Harun al-Rashid (786-809)Brief overview of Haruns life at the Jewish Virtual Library. Harun ar-RashidConcise bio at Infoplease. Harun al-Rashid in Print The links below will take you to a site where you can compare prices at booksellers across the web. More in-depth info about the book may be found by clicking on to the books page at one of the online merchants. Harun Al-Rashid and the World of a Thousand and One Nightsby Andre Clot Reinterpreting Islamic Historiography: Harun al-Rashid and the Narrative of the Abbasid Caliphate(Cambridge Studies in Islamic Civilization)by Tayeb El-Hibri

Equilibrium Concentration Example Problem

Equilibrium Concentration Example Problem This example problem demonstrates how to calculate the equilibrium concentrations from initial conditions and the reactions equilibrium constant. This equilibrium constant example concerns a reaction with a small equilibrium constant. Problem: 0.50 moles of N2 gas is mixed with 0.86 moles of O2 gas in a 2.00 L tank at 2000 K. The two gasses react to form nitric oxide gas by the reactionN2(g) O2(g) ↔ 2 NO(g).What are the equilibrium concentrations of each gas?Given: K 4.1 x 10-4 at 2000 K Solution: Step 1 -Â  Find initial concentrations: [N2]o 0.50 mol/2.00 L [N2]o 0.25 M [O2]o 0.86 mol/2.00 L [O2]o 0.43 M [NO]o 0 M Step 2 -Â  Find equilibrium concentrations using assumptions about K: The equilibrium constant K is the ratio of products to reactants. If K is a very small number, you would expect there to be more reactants than products. In this case, K 4.1 x 10-4 is a small number. In fact, the ratio indicates there are 2439 times more reactants than products. We can assume very little N2 and O2 will react to form NO. If the amount of N2 and O2 used is X, then only 2X of NO will form. This means at equilibrium, the concentrations would be [N2] [N2]o - X 0.25 M - X[O2] [O2]o - X 0.43 M - X[NO] 2XIf we assume X is negligible compared to the concentrations of the reactants, we can ignore their effects on the concentration[N2] 0.25 M - 0 0.25 M[O2] 0.43 M - 0 0.43 MSubstitute these values in the expression for the equilibrium constantK [NO]2/[N2][O2]4.1 x 10-4 [2X]2/(0.25)(0.43)4.1 x 10-4 4X2/0.10754.41 x 10-5 4X21.10 x 10-5 X23.32 x 10-3 XSubstitute X into the equilibrium concentration expressions[N2] 0.25 M[O2] 0.43 M[NO] 2X 6.64 x 10-3 MStep 3 - Test your assumption:When you make assumptions, you should test your assumption and check your answer. This assumption is valid for values of X within 5% of the concentrations of the reactants.Is X less than 5% of 0.25 M?Yes - it is 1.33% of 0.25 MIs X less than 5% of 0.43 MYes - it is 0.7% of 0.43 MPlug your answer back into the equilibrium constant equationK [NO]2/[N2][O2]K (6.64 x 10-3 M)2/(0.25 M)(0.43 M)K 4.1 x 10-4The value of K agrees with the value given at the beginning of the problem. The assumption is proven valid. If the value of X was greater than 5% of the concentration, then the quadratic equation would have to be used as in this example problem. Answer: The equilibrium concentrations of the reaction are[N2] 0.25 M[O2] 0.43 M[NO] 6.64 x 10-3 M