what is the difference between absorption and emission? transmission and reflection?

when plotting a graph of A vs B, what does it mean if one says that A is directly proportional to B? what would the graph look like?

what are the four steps of the scientific method?

You used 50.0mL of hydrochloric acid with 0.500g of magnesium. If the temperature changed from 20.0oC to 24.0oC, what was the heat of reaction (ΔH) for your experiment? Report your answer in kJ without writing the units.

QUESTION 1

Of the quantum numbers n, l, m_l, and m_s, which is the spin quantum number?

1 points   

QUESTION 2

Valence electrons are the outer electrons of an atom.

True

False

1 points   

QUESTION 3

What type of bond is between the two carbon atoms in the molecule ethane (C₂H₆)?

1 points   

QUESTION 4

A molecule has a carbon atom that is best described by sp³ hybridization. Which bond angles (in degrees) come closest to describing the carbon?

1 points   

QUESTION 5

Atoms that obey the octet rule have how many valence electrons?

1 points   

QUESTION 6

A molecule has a carbon atom that is best described by sp hybridization. How many other atoms are connected to this carbon?

1 points   

QUESTION 7

The electron configuration, 1s²2s²2p⁶ is correct for which of the following atoms.

1 points   

QUESTION 8

Choose the answer that best completes the sentence: In molecular orbital theory, a single bond consists of ______.

1 points   

QUESTION 9

The compound N₂ contains only this kind of bond.

1 points   

QUESTION 10

What is the maximum number of electrons that can be contained in the 4s orbitals?

What is the bonding functional group and elution order of the following: propyl acetate, butyl acetate, methanol, ethanol, 2-butanone, and 4-methyl-2-pentatnone

Diazomethane is a highly poisonous, explosive compound because it readily evolves N₂. Diazomethane has the following composition by mass: 28.57% C; 4.80% H; and 66.64% N. The molar mass of diazomethane is 42.04 g/mol. Find the molecular formula of diazomethane, draw its Lewis structure, and assign formal charges to each atom. Why is diazomethane not very stable? Explain.

Consider the titration of 70.0 mL of 0.0300 M (CH3)3N (a weak base; Kb = 6.40e-05) with 0.100 M HBr. Calculate the pH after the following volumes of titrant have been added:

(a) 0.0 mL

pH = _____

(b) 5.3 mL

pH = _____

(c) 10.5 mL

pH = _____

(d) 15.8 mL

pH = _____

(e) 21.0 mL

pH = _____

(f) 27.3 mL

pH = _____

Calculate the mass in grams of hydrogen chloride produced when 5.95 L of molecular hydrogen measured at STP reacts with an excess of molecular chlorine gas.

H2(g) + Cl2(g) → 2HCl(g)

At 25°C, the standard enthalpy of combustion of gaseous propane (C3H8) is –2219.0 kJ per mole of propane, and the standard enthalpy of combustion of gaseous propylene (C3H6) is –2058.3 kJ per mole of propylene. What is the standard enthalpy change for the following reaction at 25°C? C3H6(g) + H2(g) → C3H8(g) Substance ∆H°f (kJ/mol) CO2(g) –393.5 H2O(l) –285.8 a) +160.7 kJ b) –160.7 kJ c) +104.7 kJ d) –20.4 kJ e) –125.1 kJ

A 3.452 M solution of triethylamine ((C2H5)3N, Kb= 4e-4) has a pH of 12.57. What is the percent ionization of this solution?

If there is appeoximately 84,000 people living in Nampa, Idaho and there is an average of 4 people per household and that each household owns 2 cars, how much total carbon dioxide is generated (@ STP) by the residents of the city of Nmmpa each year with the following information:

(A) Each car has a 16 gallon gasoline tank

(B) Each car in each household consumes one tank ofgasoline per week (52 weeks per year)

(C) Assume that gasoline is pure benzene (C6H6) and is burned to completion in air when the tank is emptied

Q: Approx. hoow much total Liiters of CARBON DIOXIDE GAS is generated by the residents of Nampa, Idaho only driving their cars and consuming one tankful per week of gasoline in each car for each of the 52 weeks in the year?

Write the balanced molecular and net ionic equations for the reaction between solid copper and nitric acid (6M) concentration. Identify the oxidation and reduction half-reactions. How would this change if the concetration was15.8M?

Balanced molecular equation:

Ionic Equation:

Net ionic equation:

Oxidation half-reaction:

Reduction half-reaction:

Mg(s)+2HCl(aq)=MgCl2(aq)+H2(g)

(A) 0.0675g Mg AND 4mL of 6M HCl were used. Barometric pressure were 28.85 inches Hg. A volume of 73.6mL of hydrogen was collected at a temperature of 26.0C. The vapor pressure of water is 25.2mm Hg at this temperature. Calculate R, the gas law constant, in L-atom\mol-K using the information above for the reaction of HCl and Mg. 760 mmHg= 1.00atm. 1 inch=2.54 cm.

Show your calculation

(B) why is it necessary to substract the vapor pressure of the hydrogen gas formed to your experiment?

(C) If some gas was lost during the process and the measured amount of gas was less than the amount that should have been produced, would this increase or decrease the calculated R ? Explain your answer.

Data Table 1. Adding 0.1M HCl from D1 into A1.

Data Table 2. Adding 0.1M NaOH from D6 into A6.

Data Table 3. Adding 6M HCl from Pipet into B1.

Data Table 4. Adding 6M NaOH from Pipet into B6.

Data Table 5. Adding 0.1M HCl from D1 into C1.

Data Table 6. Adding 0.1M NaOH from D6 into C6.

Questions

(5pts) Discuss if you saw a buffer. Define buffer and explain, with complete sentences, what you did to shift that buffer.

(10pts) A buffer was established with 2.0mL of 0.833M acetic acid. 0.5mL of 0.1M HCl is added. What is the new pH of the buffer? Ka of acetic acid = 1.8 x 10^-5 Show your work.

Discuss in a complete sentence how your theoretical calculation here is the same or different than what was obtained in Data Table 5.