Question

Medals

Answer 1

Consider the following reaction:

2 H2S (g) Two arrows stacked on top of each other. The top arrow points to the right. The bottom arrow points to the left. 2H2 (g) + S 2 (g)

Which answer represents the equilibrium constant for this reaction?

The concentration of H subscript two to the exponent 2 multiplied by the concentration of S2 in the numerator all over the concentration of H2S to the exponent 2 in the denominator.

The concentration of H subscript two multiplied by the concentration of S2 in the numerator all over the concentration of H subscript two S in the denominator.

Two times the concentration of H subscript two multiplied by the concentration of S subscript two in the numerator all over two times the concentration of H subscript two S in the denominator.

The concentration of Hsubscript two S to the exponent 2 in the numerator all over the concentration of H subscript two multiplied by the concentration of S subscript two in the denominator.

Question 10 (Multiple Choice Worth 2 points)

[07.02]If 20.0 mL of a 0.500 M HCl solution is required to neutralize 35.0 mL KOH, what is the concentration of the KOH solution?

HCl + KOH yields KCl + H2O

0.286 M

0.572 M

1.00 M

1.14 M

Question 11 (Multiple Choice Worth 2 points)

[07.06]What is the oxidation number of sulfur (S) in sulfuric acid (H2SO4)?

-6

+2

+4

+6

Question 12 (Multiple Choice Worth 2 points)

[05.08]When dissolved in 1000 g of water, which chemical compound will produce a solution with the greatest freezing point depression?

5.0 g of sodium chloride (NaCl)

9.2 g of potassium chloride (KCl)

11 g of calcium fluoride (CaF2)

20 g of glucose (C6H12O6)

Question 13 (Multiple Choice Worth 2 points)

[08.04]Fuel cell cars that use hydrogen as fuel have the potential to be quiet, produce low emissions, and require less maintenance than gasoline cars. What negative effect might hydrogen fuel have on the environment?

Society will drive more because the fuel is cheaper and more abundant.

To produce the hydrogen, a fuel must be burned and emissions will be produced.

More cars will be on the road because they will be cheaper and less costly to drive.

Hydrogen is dangerous and many vehicles will explode before technology becomes safe.

Answer 2

@aaronq

Answer 3

@april115

Answer 4

@texaschic101

Answer 5

oh god, question overload.

okay, 1. this is the way you write equilibrium expressions

aA + bB <-> cC + dD (lower case are the coefficients, upper case are the species)

\[K=\frac{ [C]^{c}[D]^{d} }{ [A]^{a}[B]^{b} }\]
(P.s. you never include water or solids)

Answer 6

2. \[Molarity = \frac{ n _{solute} }{ L _{solution} }\]

n=moles, btw.

so, knowing this info "20.0 mL of a 0.500 M HCl" find the moles of HCl (use the equation above)

since they react in a 1:1 ratio, (i.e. KOH and HCl), the moles of HCl used are equal to the moles of KOH used.

so knowing the volume (L of solution) of KOH, 35.0 mL, and the moles (you found in the first step) find the molarity (aka concentration). Use the same equation