General Chemistry Answers

the standard enthalpy of formation of urea, CO(NH2)2(6).

The standard enthalpy of the reaction: CO(NH2)2() + H2Om) -› COz) + 2 NHare) is -133.42 kJ/mol. Calculate

You are asked to prepare a buffer solution with pH 5.10. If you start with a solution containing 10.0 mmol acetic acid (CH₃COOH, K_a = 1.8×10^-5), how many millimoles of sodium acetate (CH₃COONa) must be added to the solution?

Express your answer to three significant figures.

What is the solubility of CO2 in a soft drink (which is mainly water) that was bottled under a CO2 pressure of 4.5 atm ?

A photographic "stop bath" contains 160ml of pure acetic acid, HC2H3O2(1) in 650 ml solution

Electron Pair Geometry of:

1. H₂Se
2. PCl₄⁺
3. NO₂^-
4. BrF₃
5. I₃^-

Calculate the grams of water that must be added to 16.0 grams of sugar in the preparation of a 25.0% sugar solution

Write electron configurations for the following chemical species. Then, give which the noble gas has the same

configuration.

1. Na +

2. Mg +2

3. I -

4. Se- 2

5. Mn +7

Predict the charge of the following atoms when converted into ions. Show the mathematical equation to get

the charge of each ion.

1. Iodine

2. Sulfur

3. Zirconium

4. Ruthenium

5. Selenium

A small hole in the wing of a space shuttle requires a 17.7cm² patch

a.) What is the patch's area in space kilometers?

b.) If the patching material costs NASA USD 3.25/in², what is the cost of the patch?

N2(g)+3H2(g) --->2NH3(g)

If AH = -92.2kJ and AS= -0.1987kJ/K, what is AG for the reaction at 475 C

and at 5'C? Provide the answer in kJ. In each case, is the reaction

spontaneous?