Final Chemistry

According to the following reaction, which molecule is acting as a base?

H2O + H2SO4 → H3O+ + HSO4-

H2O

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What is the main characteristic of a strong base?

It is completely dissociated in water.

What would the concentration of OH- be if the concentration of H3O+ was 1 × 10-5 M?

[H3O+] × [OH-] = Kw = 1 × 10-14

1 × 10-9

What is pH?

It is a numerical scale used to represent acidity or basicity.
It is the negative of the log of the hydronium ion concentration.

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What is the hydroxide ion concentration in an aqueous solution when the hydronium ion concentration equals 1 × 10-10 moles per liter?

The concentration of hydroxide ions is 1 × 10-4 moles per liter.

In the following buffer system, what happens to the concentration of the highlighted molecule if you add base (OH-)?

HF + NaF + H2O ⇌ F- + Na+ + H3O+

Decreases

Carbon dioxide reacts with water to form ________.

carbonic acid

How might warmer oceans accelerate global warming?

The solubility of CO2 in water decreases as temperatures rise.

The overall rate at which humans are producing carbon dioxide is ________.

increasing

Given that [H+] = 1 x 10-8, calculate the pH

8

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How many electrons are gained or lost in the following half-reaction?

2 Na → 2 Na+

2 electrons are lost

Chemical equations need to be balanced not only in terms of the number of atoms, but also by the charge. In other words, just as there should be the same number of atoms before and after the arrow of an equation, there should be the same charge. What set of coefficients is necessary to balance the following chemical equation?


____Ce4+ + ____ Cl⁻ → ____ Ce3+ + ____ Cl2

1,2,1,1

The following set of redox reactions takes place as shown.


Container A Container B
Fe → Fe2+ + 2e- Cu2+ + 2e- → Cu


If you had two containers filled with the ion solution described above with a wire connecting a piece of iron (in container A) and a piece of copper (in container B) and a salt-bridge connecting the two containers, which way do the electrons flow?

The electrons flow from container A to container B

Which of the following statements best describes an anode?

the negatively charged electrode of a battery or electrochemical apparatus
the place where oxidation is taking place in a battery or electrochemical apparatus
the place from which electrons are flowing away from.
ALL OF THE ABOVE

What is the purpose of the salt bridge in a voltaic cell?

to allow for a balance of charge between the two chambers

In the oxidation-reduction reaction Mg(s) + Cu2+ (aq) →Mg2+ (aq) + Cu(s), which atom or ion is reduced? Which atom or ion is oxidized?

The Cu2+ ion is oxidized as it gains electrons from the copper metal, Cu. The magnesium metal, Mg, is reduced as it loses electrons to form Mg2+.

What is the primary difference between a fuel cell and a battery?

Fuel cells do not run down because they can be refueled; batteries run down and need to be recharged.

What is a hydrocarbon?

It is a molecule composed of carbon and hydrogen only.

Which of the following statements describes straight-chain hydrocarbon?

a hydrocarbon where every carbon has only a single bond to no more than two other carbons

Correctly identify the following functional groups in this organic molecule—amide, ester, ketone, ether, alcohol, aldehyde, amine.

2 = amide, 6 = aldehyde, 7 = amine, 8 = ether

Which of the following compounds is likely to have the best water solubility?

CH3CH2OH

Which of the following molecules contains a phenol?

b and c

Which of the following compounds is an amine?

all of the above

The following reaction is used to make the polymer described below. What is the other starting material?

HOCH2CH2OH

What is the first step in the scientific process?

observe a natural phenomenon

if 1ft = 12 in, how many feet is 16.0 inches?

1.33 ft

A piece of aluminum weighing 10.0 grams is placed into a graduated cylinder that has an initial volume (before immersion) of 135.0 mL. After immersion, the volume on the cylinder reads 138.7 mL. What is the density of the metal sample?

0.37 g/mL

Which of the following is an example of a physical change?

water boiling and being converted into steam

A gas at 25 C has a volume of 250 L. At what temperature (in C) will it have a volume of 100 L?

-154

what atoms is the largest?

Rb

If you mix a typical iodine ion (I, atomic no. = 53) with a typical barium ion (Ba, atomic no. = 56), what compound is formed?

Bal2

What is the molarity when water is added to 2 moles of sodium chloride to make 0.5 liter of solution?

4 M

If it takes 200 J to raise the temperature of a 10-gram block of ice by 10°C, what is the specific heat of the ice?

200 J