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Basic Chemistry 1 Final Exam Review, based off lecture and labs 6-9.

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Chemistry I Final Exam Review

Pregunta 1 de 19

1

A piece of metal weighing 59.047 g was heated to 100ºC and then put into 100 mL of water (initially at 23.7ºC). The metal and water were allowed to an equilibrium temperature, determined to be 27.8ºC. Assuming no heat lost to the environment, calculate the specific heat of the metal. Specific Heat of water = 4.18J/gºC Density of water = 1.00g/mL

Selecciona una de las siguientes respuestas posibles:

  • 0.623 J/gºC

  • 1.79 J/gºC

  • 0.402 J/gºC

  • 0.721 J/gºC

Explicación

Pregunta 2 de 19

1

In an experiment, 700 mL of 0.5 M hydrochloride acid (HCl) is added to 600 mL of of 0.5 M sodium hydroxide (NaOH) solution. The acid and base neutralize each other according to the equation: HCl + NaOH --> NaCl + H2O
How many moles of acid and base were there originally?

Selecciona una de las siguientes respuestas posibles:

  • 0.35 mole of HCl and 0.3 mole of NaOH

  • 0.08 mole of HCl and 0.18 mole of NaOH

  • 0.035 mole of HCl and 0.05 mole of NaOH

  • 0.05 mole of HCl and 0.03 mole of NaOH

Explicación

Pregunta 3 de 19

1

A chemist wants to determine the enthalpy of neutralization for the following reaction: HCl (aq) + NaOH (aq) --> NaCl (aq) + H2O (l)

The chemist uses a coffee-cup calorimeter to neutralize completely 70.5 mL of 2.56 M HCl (aq) with 30.5 mL of 2.56 M NaOH (aq). The initial temperature of both solutions is 16.8ºC. After neutralization, the highest recorded temperature is 22.6ºC. Calculate the enthalpy of neutralization in kJ/mol of H2O.
Assume that the density of the solution is 1.00 g/mL and specific heat is 4.18 J/gºC

Selecciona una de las siguientes respuestas posibles:

  • -29.2 kJ/mol

  • 29.2 kJ/mol

  • -31.4 kJ/mol

  • 31.4 kJ/mol

Explicación

Pregunta 4 de 19

1

Use the periodic table to predict which element has the largest ionization energy.

Selecciona una de las siguientes respuestas posibles:

  • H

  • He

  • Fr

  • Rn

  • Rh

Explicación

Pregunta 5 de 19

1

Use the periodic table to predict which element has the largest atomic radius.

Selecciona una de las siguientes respuestas posibles:

  • H

  • He

  • Fr

  • Rn

  • Rh

Explicación

Pregunta 6 de 19

1

Which of the following is a transition element?

Selecciona una de las siguientes respuestas posibles:

  • H

  • He

  • Fr

  • Rn

  • Rh

Explicación

Pregunta 7 de 19

1

The element germanium (Ge) is used in the manufacture of some transistors. What other element might be used for such a purpose?

Selecciona una de las siguientes respuestas posibles:

  • Ga

  • Se

  • Si

  • Pb

  • Tl

Explicación

Pregunta 8 de 19

1

When the excess of calcium carbonate is added to dilute HCl, the reaction gradually becomes slower and finally stops. Which statement best explains why this happens?

Selecciona una de las siguientes respuestas posibles:

  • An insoluble layer of calcium chloride is formed on the calcium carbonate.

  • The concentration of HCl gradually reduces to zero.

  • The pieces of calcium carbonate gradually become smaller.

  • The calcium carbonate is covered by bubbles of carbon dioxide.

Explicación

Pregunta 9 de 19

1

The molar volume of a gas-

Selecciona una de las siguientes respuestas posibles:

  • is commonly used in calculations as 22.4 L/mol at STP

  • of 22.4 L/mol at STP is considered to be absolutely true only for ideal gases

  • will change if the temperature and/or pressure change

  • All of the above are true

Explicación

Pregunta 10 de 19

1

In the reaction CH4 (g) + 2O2 (g) --> CO2 (g) + 2H2O (g)
18 L of oxygen would produce how many L of CO2 at STP?
(Hint: You must first balance the equation.)

Selecciona una de las siguientes respuestas posibles:

  • 0.40 L

  • 9 L

  • 18 L

  • 36 L

Explicación

Pregunta 11 de 19

1

A metal was found to release -1246 J of energy in a calorimeter. Initial temperature was 40.0ºC and the final temperature was 2.00ºC. The specific heat of the metal is 3.14 J/gºC, what is the mass of the metal used?

Selecciona una de las siguientes respuestas posibles:

  • 4.40 g

  • 16.5 g

  • 9.44 g

  • 10.4 g

Explicación

Pregunta 12 de 19

1

What is the mass in grams of 17.0 liters of methane gas (CH4) at STP?
MM of CH4 = 16.04 g/mol

Selecciona una de las siguientes respuestas posibles:

  • 0.0473 g

  • 23.7 g

  • 6100 g

  • 12.2 g

Explicación

Pregunta 13 de 19

1

During a Carbonate Analysis experiment, a 0.306 g sample of a CaCO3 "mixture" was used to collect 0.061 g CO2. Determine the mass of CaCo3 in the original mixture.
CaCO3 (g) + 2H3O+ (aq) --> Ca2+ (aq) + 2H2O (l) + CO2 (g)
MM of CaCO3 = 100.09 g/mol
MM of Co2 = 44.01 g/mol

Selecciona una de las siguientes respuestas posibles:

  • 43.8 %

  • 75.6%

  • 45.4 %

  • 78.4 %

Explicación

Pregunta 14 de 19

1

A 3 M HCl solution was used to generate the CO2 from the CaCO3 mixture. What would be the effect on the calculations if 6 M HCl was substituted for the 3 M HCl?

Selecciona una de las siguientes respuestas posibles:

  • no affect as long as the 3 M HCl is in access

  • calculations would be too low

  • calculations would be too high

  • calculations can not be completed

Explicación

Pregunta 15 de 19

1

Electrons are lost by the-

Selecciona una de las siguientes respuestas posibles:

  • reducing agent as it undergoes oxidation

  • reducing agent as it undergoes reduction

  • oxidizing agent as it undergoes oxidation

  • oxidizing agent as it undergoes reduction

Explicación

Pregunta 16 de 19

1

Phenolphthalein is ______ in basic solutions but _____ in acidic solutions.

Selecciona una de las siguientes respuestas posibles:

  • pink; colorless

  • blue; colorless

  • colorless; blue

  • colorless; pink

Explicación

Pregunta 17 de 19

1

In a titration, 34.12 mL of HCl required 42.03 mL of a 0.9981 M NaOH solution to reach the endpoint. Calculate moles of NaOH dispensed.

Selecciona una de las siguientes respuestas posibles:

  • 0.03406 mol

  • 1.229 mol

  • 0.04195 mol

  • 41.95 mol

Explicación

Pregunta 18 de 19

1

What is the difference between the endpoint and stoichiometric point in a strong acid/base titration?

Selecciona una de las siguientes respuestas posibles:

  • The endpoint is when the pH is exactly 7

  • The stoichiometric point is when the pH is exactly 7

  • The endpoint and the equivalence point are the same thing

  • None of these answers are correct

Explicación

Pregunta 19 de 19

1

At 16.7 mL volume of a 0.0861 M NaOH solution neutralizes 20.0 mL of HCl acid. What is the molar concentration of the HCl solution?

Selecciona una de las siguientes respuestas posibles:

  • 0.0710 M

  • 0.0625 M

  • 0.0725 M

  • 0.0719 M

Explicación