ENPE_381_Set-1-2010-Solution

Jj.70.

A compound contains, by mass, 81.7% carbon and 18.3% hydrogen. A 0.15 mole sample of this compound weighs 6.6 g. What is the molecular formula of this compound? C2H6 CH3 C3H12 C4H10 C3H8

how do you solve  ______C10H14N2(s)+ ______O2(g)---->____CO2(g)+____H2O(l)+_____NO2(g)?

How many grams of N2 are needed to make 444 g of NBr3 ?  N2   +   3 Br2   →   2 NBr3   +   44.0 kJ              The molar mass of NBr3 is 253.719 g and the molar mass of N2 is 28.013 g                        _______________ mol NBr3                                                                                   (444 g NBr3)(–––––––––––––––––––––––––)  = ______________  mol NBr3                        ____________________ g NBr3                                                                                                                                          _______________ mol N2    _______________ mol NBr3 (–––––––––––––––––––––––––) =  ___________---- mol N2                                                        _________________ mol NBr3                                                            _______________  g N2 _____________________ mol N2 (–––––––––––––––––––––––––) = ___________________  g N2                                                       __________________ mol…

A local water retention pond was found to have elevated levels of mercury concentrated as 14 ng per liter. You would like to collect some mercury for your homemade perpetuum mobile machine. How many moles of mercury can you get you collect and process the entire volume of 1250 m3 of the water in the pond? 1.8 x 10-5 moles 4.4 x 10:5 moles 1.8 x 10-2 moles 8.7 x 108 moles 7.6 x 10-5 moles O 4.4 x 108 moles 8.7 x 105 moles

To help farmers and gardeners , commercial fertilizers have a big three -number "NPK" label on the bag that gives the amounts of three key plant nutrients: nitrogen , phosphorus and potassium. For example , a bag of "-10-10-10" fertilizer has 10% by mass nitrogen , 10% by mass potassium as potash (K2O), and 10% by mass phosphorus as phosphate (P2O5). Suppose a certain fertilizer has the following composition. What should the first (nitrogen) number on the bag label be? That is, calculate the the percent by mass of nitrogen in this fertilizer. Round your answer to the nearest percent.

: ny F1 ! Q What does a complete balanced chemical equation include? O F2 molar coefficients valence electrons exothermic coefficients 2 endothermic coefficients -0- @ W F3 -Ő+ #m 3 E F4 $ 4 F5 R % F6 T Q F7 6 Y F8 & 7 F9 *00 U 8 H

Chap 2 question 1

12. Sulfur dioxide will react with water to form sulfurous acid (see balanced equation below). So2(g) + H2O(1) –→ H2SO3(1) What mass of sulfur dioxide is needed to prepare 75.85 g of H2SO3(1)? Molar Mass of H2so3(1) - 82.07g/mol Molar Mass of SO2(g) - 64.07 g/mol 13. How many grams of oxygen can be obtained by the determination of 456 g of reactant in the following reaction: 2Hgo – 2Hg + 02 Molar Mass: Hg: 200.59 g/mol O: 16 g/mol| 14. How many grams of reactant are needed to obtain 97 g of oxygen in the following reaction? KCIO4 – KCI + 202 Molar Mass: K: 39.10 g/mol CI: 35.45 g/mol O: 16 g/mol 15. A reaction mixture contains 21.4 g of PC13 and 13.65 g of PBF2. What mass of PbC12 can be obtained from the reaction? Molar Mass: P: 30.97 g/mol CI: 35.45 g/mol Pb: 207.2 g/mol F: 19 g/mol 16. When 0.56 grams of CuC12 reacts with 0.64 grams of KI, how many grams of 12 is formed? Given reaction: CuC12 + KI – Cul + KCI + 12 MM CUCI2 = 110.98 g/mol MM KI = 166 g/mol MM 12 = 253.81 g/mol

Equivalent weight of Al(OH)3 is а. 39 g O b. 27 g c. 78 g O d. 26 g

Calculate the number of moles in a 7.89 kg sample of aspirin.

OH 10% КОН CH3 water, boll N

answer the following questions

3. Molly Cule weighed 8.61g of her hydrate (which is CaSO4*2H2O). After she did her hydrates lab, she found that her anhydrate weighed 6.81g. A) If Molly has not completely dried her samples before weighing her anhydrate, how would her final calculations of mole ratio of water to anhydrate be affected? B) How many moles of water were lost during the lab due to evaporation?

Given the unbalanced chemical equation, CH3OH(l)  +  O2(g) →  CO2(g)  +  H2O(g),  what is the mole ratio between CH3OH and CO2 (CH3OH:CO2)?   Group of answer choices A. 1:1 B. 1:2 C. 2:1 D. 3:2

13. All about acetaminophen (Tylenol). The chemical formula of acetaminophen is C₂H₂NO₂. Acetaminophen is a very effective drug for general pain and headaches whose major side effect is liver toxicity. a. What is the molar mass of acetaminophen? H3C b. What is the mass of 1 molecule of acetaminophen in amu? C. 'N How many grams of acetaminophen are in 5.8 moles of acetaminophen? d. How many oxygen atoms are in 629 grams of acetaminophen? LOH e. If a sample of acetaminophen contains 81 hydrogen atoms, how many molecules of acetaminophen are in the sample?

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How many grams of NBr3 can be made from 2.22 x 102 moles of Br2? N2 + 3 Br2 2 NB13 + 44.0 kJ The molar mass of NBR3 is g mol NB33 (2.22 x 102 mol Br2)(- -) = mol NBR3 mol Br2 g NB13 mol NB13 -) = g NBR3 mol NBR3 а. 1 b. 2 С. 3 d. 4 е. 5 f. 253.719 g. 3.76 x 10° h. 3.26 x 103 i. 44.0 j. 1.48 x 102 k. 9.77 x 103 I. 4.44 x 102 m. 6.66 x 10² n. 500.0 0. 556 р. 90.0 q. 3.2852 r. 159.81 S. 28.013 t. 1.750 u. 0.8750 V. 13.0 w. 0.46306 X. 1.3892 у. 24.5 Z. 38.5 аа. 2.190 bb. evolved CC. absorbed dd. exothermic ee. endothermic