Qualitative analysis Questions and Answers

Calculate ΔH for the following reactions using bond enthalpies a. 2CO(g) + O2(g) →→2CO2(g) b. C₂H2(g) + H2(g) → C₂H4(g) c. 4NH3(g) + 5O2(g) →→ 4NO(g) + 6H₂O(g) d. Br2(g) + CH4(g) → CH3Br(g) + HBr(g)

A metal cylinder with a fixed volume was filled with gas to 4.00 atm pressure at room temperature, 30.0 C. The cylinder was then taken outside on a cold winter day where the temperature was -30.0 C. What is the pressure inside the cylinder?

What would you need to do to make a 13% solution of sodium chloride (NaCl)? Add 26 g of sodium chloride to a beaker and add water to make a final volume of 200 mL. Add 13 g of sodium chloride to 100 mL of water. Add 13 g of sodium chloride to a beaker and add water to make a final volume of 100 mL. Add 26 g of sodium chloride to 200 mL of water.

Benzoic acid C6H5COOH has a heat of combustion of -3227kJ/mol. A 1.221g- sample burns in a calorimeter that has a heat capacity of 1365J/°C, and which contains 1.200kg of water. What temperature change is observed in the calorimeter?

When burning ethanol in a closed system, which of the following is the best claim and reasoning? The ethanol reaction stops because a bromthymol blue solution that's present turns the same color as when ethanol vapor is blown into the solution Evaporated ethanol is produced because it burns. Water is produced because a bromthymol blue solution that's present turns the same color as when water vapor is blown into the solution. Carbon dioxide is produced because a bromthymol blue solution that's present tums the same color as when carbon dioxide is blown into the solution. " 1 2 3 4 5 6 8 9 10

a) [NiH4]²- b) N3 c) Mo(CO) 6 d) PC|3l2 e) SiO44- For each of the molecules selected: Draw the correct molecular geometry, including resonance structures if appropriate. Provide the point group and the main symmetry elements (besides E). Determine the polarity of the molecule and the direction of the dipole.

An unknown weight of the aluminum sample (Al) was placed in the hydrobromic acid solution. The reaction was as follows: 2 Al (s) + 6 HBr (aq) -> 2 AlBr3 (s) + 3 H2(g) What was the mass of the Al sample (in grams) if a 14.4 L of the gas product of this reaction was collected at the temperature of 520.0°C and under the pressure of 741 mmHg? Molar masses (in g/mole): Al = 26.98; HCI=80.91; AICI3 = 266.69;H₂=2.00 Guiding questions: The temperature in K was The pressure in atm was The number of moles of gas was The mass of the Al sample was

A "dimer" forms when two of the same molecules combine (dimerize). Draw a Lewis structure for each of the substances below and indicate which are free radicals. For a free radical the unpaired electron goes on the least electronegative element, which is usually the central atom. C103 C103 CIO2 NO₂

How many grams of phosphorus (P4) are needed to completely consume 38.8 L of chlorine gas according to the following reaction at 25 °C and 1 atm? phosphorus (P4) (s) + chlorine (g) phosphorus trichloride (l)

Why does Neiterkob's daughter most likely tell the myth "The Beginnings of the Maasai"? to entertain the reader with the fantastic setting of where the Maasai live to persuade the reader to adopt the Maasai's affection for the sky god to explain to the reader the origin of Maasai culture to impress the reader with the history of the Maasai

In which period of the periodic table do the elements have a "core-electron configuration" that is the same as argon. Fourth Third First Second

When p-block atoms become ions their ionic electron configurations will be identical to the Nobel Gas in the preceding period. True False

Write the 4 quantum numbers for iron's LAST valence electron for iron. n = l = ml= ms=

In the experiment performed for the determination of cholesterol, the function of the calibration curve obtained using 25-400mg/dL standard cholesterol solutions were determined as y= 0.0009x. If the amount of cholesterol in the serum sample is determined as 3.11 g/L, what is the absorbance value of the sample? 0.208 0.280 0.820 0.802

Which verb agrees with the subject? Grace _ very happy today. were is are

Complete the sentence with the correct form of the verb. This week's The National Enquirer claims that there _ photographs of the Loch Ness Monster eating Elvis. were is has