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3 years ago

12

Which car traveled a greater distance? Car A traveled 25 miles/hour for 3 hours, stopped for an hour, and then traveled 35 miles

/hour for 4 hours. Car B traveled an average speed of 43 miles/hour for 5 hours. Explain your answer.

1 answer:

Ivenika [448]3 years ago

7 0

Answer:

car b

Explanation:

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Consider the following reaction where Kc = 1.80×10-2 at 698 K:

Klio2033 [76]

Answer:

The system is not in equilibrium and the reaction must run in the forward direction to reach equilibrium.

Explanation:

The reaction quotient Qc is a measure of the relative amount of products and reagents present in a reaction at any given time, which is calculated in a reaction that may not yet have reached equilibrium.

For the reversible reaction aA + bB⇔ cC + dD, where a, b, c and d are the stoichiometric coefficients of the balanced equation, Qc is calculated by:

$Qc=\frac{[C]^{c}*[D]^{d} } {[A]^{a}*[B]^{b}}$

In this case:

$Qc=\frac{[H_{2} ]*[I_{2} ] } {[HI]^{2}}$

Since molarity is the concentration of a solution expressed in the number of moles dissolved per liter of solution, you have:

$[H_{2} ]=\frac{2.09*10^{-2} moles}{1 Liter}$ =2.09*10⁻² $\frac{moles}{liter}$

$[I_{2} ]=\frac{4.14*10^{-2} moles}{1 Liter}$ =4.14*10⁻² $\frac{moles}{liter}$

$[I_{2} ]=\frac{0.280 moles}{1 Liter}$ = 0.280 $\frac{moles}{liter}$

So,

$Qc=\frac{2.09*10^{-2} *4.14*10^{-2} } {0.280^{2} }$

Qc= 0.011

Comparing Qc with Kc allows to find out the status and evolution of the system:

If the reaction quotient is equal to the equilibrium constant, Qc = Kc, the system has reached chemical equilibrium.

If the reaction quotient is greater than the equilibrium constant, Qc> Kc, the system is not in equilibrium. In this case the direct reaction predominates and there will be more product present than what is obtained at equilibrium. Therefore, this product is used to promote the reverse reaction and reach equilibrium. The system will then evolve to the left to increase the reagent concentration.

If the reaction quotient is less than the equilibrium constant, Qc <Kc, the system is not in equilibrium. The concentration of the reagents is higher than it would be at equilibrium, so the direct reaction predominates. Thus, the system will evolve to the right to increase the concentration of products.

Being Qc=0.011 and Kc=1.80⁻²=0.018, then Qc<Kc. <u><em>The system is not in equilibrium and the reaction must run in the forward direction to reach equilibrium.</em></u>

8 0

3 years ago

Explain how you determine the freezing point of a solution that does not have a well-defined transition in the cooling curve.

Sophie [7]

This question is asking for a method for the determination of the freezing point in a solution that does not have a noticeable transition in the cooling curve, which is basically based on a linear fit method.

The first step, would be to understand that when the transition is well-defined as the one on the attached file, we can just identify the temperature by just reading the value on the graph, at the time the slope has a pronounced change. For instance, on the attached, the transition occurs after about 43 seconds and the freezing point will be about 4 °C.

However, when we cannot identify a pronounced change in the slope, it will be necessary to use a linear fit method (such as minimum squares) to figure out the equation for each segmented line having a significantly different slope and then equal them so that we can numerically solve for the intercept.

As an example, imagine two of the segmented lines have the following equations after applying the linear fit method:

$y=-3.5 x + 25\\\\y=-0.52 x + 2$

First of all, we equal them to find the x-value, in this case the time at which the freezing point takes place:

$-3.5 x + 25=-0.52 x + 2\\\\-3.5 x+0.52 x =2-25\\\\x=\frac{-23}{-2.98}=7.72$

Next, we plug it in in any of the trendlines to obtain the freezing point as the y-value:

$y=-3.5 (7.72) + 25\\\\y = 1.84$

This means the freezing point takes place after 7.72 second of cooling and is about 1.84 °C. Now you can replicate it for any not well-defined cooling curve.

Learn more:

7 0

3 years ago

What are the mole ratios of hydrazine

juin [17]

mole ratios of hydrazine should be 1:2. I could be wrong. Are there any options to choose from?

5 0

3 years ago

There are two steps in the extraction of copper metal from chalcocite, a copper ore. In the first step, copper(I) sulfide and ox

maxonik [38]

Answer:

2Cu2S + 3O2 + 2C -------> 4Cu + 2SO2 + 2CO

Explanation:

Equation 1 should correctly be written as;

2Cu2S + 3O2-----> 2Cu2O + 2SO2

Equation 2 should be correctly written as;

2Cu2O + 2C -----> 4Cu + 2CO

The overall reaction equation is;

2Cu2S + 3O2 + 2C -------> 4Cu + 2SO2 + 2CO

Note that species that are intermediates are cancelled out .

4 0

2 years ago

In most cases of fischer esterification, the carboxylic acid is the more "valuable" piece and the alcohol is used in excess. let

Daniel [21]

There are a lot of separation processes. To name a few, these can be distillation, centrifugation, extraction, membrane or sorption process and many other. To know which is the best technique, you should know the property between two substances that have a stark difference. In this case, it is the polarity. Ethyl alcohol is more polar than ethyl ester and less dense. Thus, these two won't mix. So, take advantage of their density difference by decantation or centrifugation.

4 0

3 years ago