Lesa

I know I need to use the half angle formula cos theta/2= +/- sqrt((1+cos theta)/2), so then I have +/-sqrt((1+cos theta)/2)-cos theta=0, but I am unsure of where to go from here.

a. 60 degrees, 300 degrees

b. 210 degrees

c. 0 degrees, 240 degrees

d. 330 degrees

e. 120 degrees

I'm not sure how to solve this so any help would be great

I feel dumb asking this but I am bad solving simple problems involving pi. For example, I need to solve a simple proportion: theta/2pi=50/60 for theta. I know you cross multiply but I really don t know how to solve for theta in radians, just because of the pi involved. I know it s dumb.

tan(sin^-1*6x)

a. cos 6 theta/sin 3 theta cos 3 theta +1

b. cos^2*3 theta/sin 6 theta cos 6 theta

c. cos 6 theta/sin 3 theta cos 3 theta

d. cos 6 theta-1/sin 3 theta cos 3 theta

e. cos 3 theta+sin 6 theta/sin 3 theta cos 6 theta

a. cos3x-cos8x/sin3x-sin8x

b. cos3x+cos7x/sin3x-sin7x

c. cos3x-cos12x/sin3x+sin12x

d. cos3x-cos9x/sin3x-sin9x

e. cos3x-cos13x/sin3x-sin13x

Zinc reacts with aqueous sulfuric acid to from hydrogen gas:

Zn(s)+H2SO4(aq)-->ZnSO4(aq)+H2(g)

In an experiment, 177mL of wet H2 is collected over water at 27 degrees clecius and a barometric pressure of 766 torr. The vapor pressure of water at 27 degrees Celsius is 26.74 torr. The partial pressure of hydrogen in this experiment is ___atm.

a)739

b)1.01

c)793

d)0.972

e)1.04

A vessel containing Ne(g) and Ar(g) has a total pressure of 9.78. If the partial pressure of the Neon (PNe) is 3.78 and the patial pressure of the Argon(PAr) is6, then the mole-fraction of Ne(g) is___ and the mole-fraction of Ar(g) is___

a)0.63,1.59

b)0.39,0.61

c)2.59,1.63

d)0.61,0.39

e)37,58.7

I know that I want to major in psychology and then pursue a masters in either social work or counseling. However, I'm not sure what I want to minor in. Anyone have any suggestions of a good minor that would be best for this career path?

I really want to pursue a degree in psychology and then a masters in either social work or some kind of counseling. However everyone I talk to or everything I look at online says that this is a very low paying career path with low job prospects. However, this is all I really want to do, nothing else really interests me as I want to directly help people solve their problems. I just don't want to end up dirt poor or struggling to find a job?

-Has anyone had any experience in these fields? Were they good or bad?

-If I get my Master's degree, will that help my pay and job prospects?

-Anyone have any advice on what a good career option would be within this realm?

A student mixes 5.00 mL 2.00 × 10−3 M Fe(NO3)3 with 3.00 mL 2.00 × 10−3 M KSCN. She finds that

in the equilibrium mixture the concentration of FeSCN2+ is 1.28 × 10−4 M.

The equation is:Fe^3+ (aq) + SCN^- (aq) ---> FeSCN^2+ (aq)

a)Find the number of moles Fe3+ and SCN− initially present.

b)How many moles of FeSCN2+ are in the mixture at equilibrium? What is the volume of the equilibrium mixture?

c)How many moles of Fe3+ and SCN− are used up in making the FeSCN2+?

d)How many moles of Fe3+ and SCN− remain in the solution at equilibrium?

e)What are the concentrations of Fe3+, SCN−, and FeSCN2+ at equilibrium? What is the volume

of the equilibrium mixture?

f)What is the value of Kc for the reaction?

A chemist examining the conversion of methane to other fuels was investigating the following reaction describing the reaction of methane with steam at 1200K:

CH4(g)+H2O(g)--><--CO(g)+3H2(g)

Kc=0.26 at 1200K

The chemist simultaneously injected 1.8 moles of each gas(CH4,H2O,CO,and H2) into a 2.00 liter flask held at 1200K.

a)In which direction will the reaction proceed in order to reach equilibrium? Why?

b)The chemist is interested in the concentration of H2 produced at equilibrium. Provide an algebraic expression whose solution would enable this concentration to be determined. Explicitly describe how the H2 could be determined from the solution of this equation? DO NOT SOLVE THE EQUATION

Sulfur dioxide reacts with molecular oxygen to form sulfur trioxide.

2SO2(g)+O2(g)--><--2SO3(g)

At some temperature the equilibrium constant for this reaction is 16. If 1.0 mole of SO2, 1.8 mole of O2, and 4.0 mole of SO3 are placed in a 2.0L flask at this temperature.

a)Will the reaction proceed to the left or the right?

b)Set up the equation that will enable you to determine the concentrations of SO3, O2, and SO3 at equilibrium (use "x") Do not attempt to solve the equation

c)Estimate a value for x in moles without doing any further calculation.

What is the molecularity of each of the following elementary reactions? write the rate law for each

a) 2NO(g)-->N2O2(g)

b)SO3(g)-->SO2(g) +O(g)

Indicate whether each is true or false:

a)If you measure the rate constant for a reaction at different temperatures, you can calculate the overall enthalpy change for the reactions

b)If you double the temperature for a reaction, you cut the activation energy in half

The density of toluene (C7H8) is 0.867 g/mL, and the density of thiophene (C4H4S) is 1.065 g/mL. A solution is made by dissolving 8.10 g of thiophene in 250.0 mL of toluene.

a)Calculate the mole fraction of thiophene in the solution

b)Calculate the molality of thiophene in the solution

c)Assuming that the volumes of the solute and solvent are additive, what is the molarity of thiophene in the solution?

A student determines the molar mass of methanol, CH3OH, by the method used in this experiment. She found that the equilibrium temperature of a mixture of ice and pure water was 0.4 degrees Celsius on her thermometer. When she added 10.0g of her sample to the mixture, the temperature, after thorough stirring, fell to -5.4 degrees Celsius. She then poured off the solution through a screen into a beaker. The mass of the solution was 101.8g.

a)What was the freezing point depression?

b)What was the molality of the methanol?

c)How much methanol was in the decanted solution?

d)How much water was in the decanted solution?

What were some of the consequences of the influenza pandemic of 1918? What did it represent? Ex) Start of globalization, etc.

Consider the following equation:

Ca^+(g) + e^--->Ca(g)

Which of the following statements are true?

a)The energy change for this process is the electron affinity of the Ca+ ion.

b)The energy change for this process is the negative of the first ionization energy of the Ca atom

c)The energy change for this process is the negative of the electron affinity of the Ca atom