General Chemistry Answers

Calculate the standard entropy changes for the following reactions at 25°C:

a) H2(g) + CuO(s) → Cu(s) + H2O(g)

b) 2Al(s) + 3ZnO(s) → Al2O3(s) + 3Zn(s)

c) CH4(g) + 2O2(g) → CO2(g) + 2H2O(l)

d) S(s) + O2(g) → SO2(g)

e) MgCO3(s) → MgO(s) + CO2(g)

A blood sample contains 0.040 g glucose (C₆H₁₂O₆) per 100.0 mL. What is the molarity of glucose in this sample?

Performance Task #5: Saving Chemistry

Below is the enhanced text of chemistry set problems gathered from the notes of Antoine Laurent Lavoisier during the accident. Please do your best to help by answering the problems and showing your solutions.

I- Part : Concept of Mole

1.      A chemist has a jar containing 388.2 g of iron filings. How many moles of iron does the jar contain?

2.      A student needs 0.366 mol of zinc for a reaction. What mass of zinc in grams should the student obtain?

3.      Calculate the mass of aluminum that would have the same number of atoms as 6.35 g of cadmium.

4.      The weight of a diamond is given in carats. One carat is equivalent to 200. mg. A pure diamond is made up entirely of carbon atoms. How many carbon atoms make up a 1.00 carat diamond?

5.      Precious metals are commonly measured in troy ounces. A troy ounce is equivalent to 31.1 g. How many moles are in a troy ounce of gold? How many moles are in a troy ounce of platinum? of silver?

How much Sodium Phosphate do we need to add to the water over 1 day in grams, to remove the dissolved iron.

The recomended concentration of sodium phosphate is 7.0mg/L

The amount of iron dissolved in the water is 13.84mg/L

4 300 000L of water go through the city each day.

96.0 g. of a gas occupies 48.0 L at 700.0 mm Hg and 20.0°C. What is its molar mass?

For the following reaction:

A_(aq) + 2 B_(aq) ⇌ 2 C_(aq) + 2 D_(aq)

Calculate the magnitude of K_c (don't report the units) assuming the following composition at equilibrium:

[A] = 0.876 mol L^-1

[B] = 0.708 mol L^-1

[C] = 0.929 mol L^-1

[D] = 0.328 mol L^-1

A nurse practitioner Orders Medrol to be given 2.0 mg per kilogram of body weight if a child weigh 69.4 pounds in the available stock of Medrol is 20 mg/mL how many milliliters does the nurse administer to the child

I have 130 liters of gas in a piston at a temperature of 250 o C. If

I cool the gas until the volume decreases to 85 liters, what will

temperature of the gas be?

If 15.0 liters of oxygen at STP are heated to 500 o C, what will be

the new volume of gas if the pressure is also increased to 1620

mmHg?

A bag of potato chips is packaged in a factory at 101.3 kPa

and has a volume of 350 mL. If this bag of chips is transported

to a city with a at a higher altitude (0.889 atm), what will the

new volume of the bag be?