Chemistry

Zapen and Nomenclature

100

Write the formula of Iron (III) oxide

Fe₂O₃

200

What is the n° of Zn

35 moles

300

Write the name of CaCO₃

Calcium Carbonate

400

Electronic configuration of the calcium

1s²2s²2p⁶3s²3p⁶4s²

500

Electronic configuration of the iron

1s²2s²2p⁶3s²3p⁶3d⁶4s²

Gases laws

100

The initial volume of a certain amount of gas is 200 cm³ at the temperature of 20 ° C. Calculate the volume at 90 ° C if the pressure remains constant

247 cm³

200

A certain amount of gas is at a pressure of 790 mm Hg when the temperature is 25º C. Calculate the pressure it will reach if the temperature rises to 200º C

6320 mmHg

300

A quantity of gas occupies a volume of 80 cm³ and a pressure of 750 mm Hg. What volume will it occupy at a pressure of 1.2 atm if the temperature remains constant?

65.33 cm³

400

2. A mass of hydrogen gas occupies a volume of 230 liters in a tank at a pressure of 1.5 atmospheres and at a temperature of 35 ° C. Calculate. How many moles of hydrogen do you have?

13.64 moles

500

A balloon is inflated with 2.42 L of helium at a temperature of 27°C. Later, the volume of the balloon has changed to 2.37 L at a temperature of 19°C and a pressure of 99.7 kPa. What was the pressure when the balloon was inflated?

100 kPa

Balance

100

Al + N₂  =  AlN

2Al + N₂  =  2AlN

200

N₂O₅ + H₂O  =  HNO₃

N₂O₅ + H₂O  =  2HNO₃

300

PbCl₄ + H₂O  =  PbO₂ + HCl

PbCl₄ + 2H₂O  =  PbO₂ + 4HCl

400

Ag + HNO₃ → AgNO₃ + NO₂ + H₂O

Ag + 2HNO₃ → AgNO₃ + NO₂ + H₂O

500

Na₂SO_{4 +} C → CO₂ + Na₂S

Na₂SO_{4 +} 2C → 2CO₂ + Na₂S

Entropy, Entalpy, Hess law and gibbs

100

Calculate the △°H of

2P + 3Cl₂ → 2PCl₃

a) P + Cl₂ → PCl₂    △°H= -297 KJ

b) 2PCl₂ + Cl₂ → 2PCl₃     △°H= -198 KJ

△°H= -792 KJ

200

Calculate the △°H of

CO + NO → CO₂ + 1/2 N₂

a) CO + 1/2 O₂ → CO₂     △°H= -283 KJ

b) N₂ + O₂ → 2NO           △°H= 180 KJ

△°H= -373 KJ

300

Calculate △°S of 

2Al + 3ZnO → Al₂O₃ + Zn

△°S Al= 28.3 JK^-1mol^-1

△°S ZnO= 43.9 JK^-1mol^-1

△°S Al₂O₃= 50.99 JK^-1mol^-1

△°S Zn= 41.6  JK^-1mol^-1

△°S= -13.3 JK^-1mol^-1

400

Calculate H and S for the following reaction and decide in which direction each of these factors will drive the reaction.

N₂ + 3H₂ → 2NH₃

△°S= -198.75 KJ/mol

500

Calculate the △°H of

2Al + Fe₂O₃ → 2Fe + Al₂O₃

△°H_f Al= 0 kJ mol^-1

△°H_f Fe₂O₃= -824.2 kJ mol^-1

△°H_f Fe= 0 kJ mol^-1

△°H_f Al₂O₃= -1675.7 kJ mol^-1

△°H= -2499.9 kJ mol^-1

pH

100

The pH of the rainwater collected in a certain area of the City of Querétaro on a peculiar day was 4.82. Calculate the concentration of H+ ions in rainwater.

m: 1.513X10-5 mol/L

200

In a NaOH solution the [OH-] is 2.9x10-4M. Calculate the pH of the solution.

pH: 10.46

300

What is the pH of a 0.001 M solution of H2SO4? HSO4- has a Ka of 1.2 x 10-2

pH: 2.73

400

What amount of NaOH (in grams) is needed to prepare 546 ml of a solution with a pH of 10.0?

m: 2.1X10-9 g

500

What molarity and what pH would 60mL of a HNO3 solution have 0.030g of HNO3?

M: .030 M

pH: 2.1004