define variables in sin(theta)= (n * lamda)/d for Chemical grating, Emission spectra

Please use sig figs and dimensional analysis and explain process!

1. Dissolve 69.0 g NaNO₂ in 1.00 x 10² mL H₂O.

(a) If the temperature of the solution is 100°C, what is the vapor pressure above the solution? The density of H₂O at 100°C is 0.9591 g/mL.

(b) Calculate the change in the boiling point of the solution, and calculate the boiling point of the aqueous solution.

(c) Calculate the freezing point of the solution. The density of H₂O at 0°C is 0.9998 g/mL.

(d) Which change is greater, the boiling point elevation or the freezing point depression?

(e) Estimate the osmotic pressure at 25 °C for the solution. Assume that dissolved sodium nitrite does not affect the volume of the solution.

What detector system would be best to use for I-131 in a mixture of all the I isotopes? Explain why.

Consider the following equilibrium.
CS2(g) + 3 O2(g) equilibrium reaction arrow CO2(g) + 2 SO2(g)
If the reaction is started in a container with 5.59 atm CS2 and 13.3 atm O2, what is Kp if the partial pressure of CO2 is 3.76 atm at equilibrium? (There is no change in temperature and the initial partial pressures of the products are equal to 0.)

Calculate the pH and the pOH of an aqueous solution that is 0.025 M in HCl ( aq ) and 0.085 M in HBr ( aq ) at 25 °C.

p H =

p O H =

1) An aqueous solution contains 0.34 M nitrous acid.

One Liter of this solution could be converted into a buffer by the addition of:

(Assume that the volume remains constant as each substance is added.)

0.17 mol HCl

0.35 mol HCl

0.35 mol KNO₂

0.086 mol Ca(OH)₂

0.34 mol KCl

2)  

An aqueous solution contains 0.26 M ammonium chloride.

One liter of this solution could be converted into a buffer by the addition of:

(Assume that the volume remains constant as each substance is added.)

0.25 mol NH₃

0.06 mol Ba(OH)₂

0.25 mol KCl

0.26 mol HI

0.12 mol HI

Calculate ΔH° for the reaction C4H4(g) + 2H2(g) → C4H8(g), using the following data:

ΔH°combustion for C4H4(g) = –2341 kJ/mol

ΔH°combustion for H2(g) = –286 kJ/mol

ΔH°combustion for C4H8(g) = –2755 kJ/mol

A) –128 kJ

B) 158 kJ

C) –158 kJ

D) 128 kJ

E) None of these choices are correct.

Calculate the theoretical yield of Cu(NH3)4SO4∙H2O (MW = 245.7g/mol) based on 10.0g of CuSO4∙5H2O (MW = 249.7g/mol).

A sample weighing 3.082 g is a mixture of Fe2O3 (molar mass = 159.69) and Al2O3 (molar mass = 101.96). When heat and a stream of H2 gas is applied to the sample, the Fe2O3 reacts to form metallic Fe and H2O(g). The Al2O3 does not react. If the sample residue (the solid species remaining after the reaction) weighs 2.637 g, what is the mass fraction of Fe2O3 in the original sample?

in boiling point determination, you first raise the temperature until bubbles starts to come out of the glass bell. at this temperature when bubbles are coming out of the glass bell, is your temperature higher or lower than the actual boiling point? explain.

Paper chromatography lab experiment. (color dye)

in the solvent system that you use for analyzing your unknown a)name the important intermolecular forces acting between the dye and the solvent and b)the dye and stationary phase for (i) the dye with the largest Rf value (ii) the dye with the smallest Rf value. comment on the relative important of the types of the forces that result in observe Rf value. c) what statical test could you apply to give some quatitation of your confidence that your known and unknown have the same Rf value?

Calculate the cell potential for the following reaction as written at 25.00 °C, given that [Zn2 ] = 0.763 M and [Sn2 ] = 0.0140 M. Standard reduction potentials can be found here.

Zn(s)+SN²⁺ YIELDS Zn²⁺(aq)+Sn(s)

1.)Glucose has a solubility of 125 g /100 mL. What is the approximate concentration of glucose in a saturated solution? How much glucose can be dissolved in 745 mL of water?

Glucose_____M
Glucose_____g

2.) Determine whether the following salts or molecules will have higher or lower solubility in water at higher temperatures.

KCl(s) + H2O(l)----> KCl(aq), ?Hrxn > 0 ____________
NH3(g) + H2O(l)---> NH3(aq), ?Hrxn< 0 ____________

3.) BaF2 has a Ksp of 2.45 x 10-5. What is the solubility of BaF2? What is the F- concentration in a saturated barium fluoride solution?

Solubility of barium fluoride ___________
[F-]= ___________

Propane (C3H8) is often used for barbeque and heating.
(a) Determine the density (in g/L) of propane at STP assuming propane behaves as an ideal gas.

(b) Determine the density (in g/L) of propane at 21.1oC and 0.912 atm assuming propane behaves as an ideal gas.