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3 years ago

Provide at least three reasons why friction is needed.

2 answers:

6 0

Friction occurs when two surfaces come into contact. Excess friction hinders movement, and it wastes energy. Friction refers to a force that opposes motion. It is important because it is applied in almost all life processes.

levacccp [35]3 years ago

4 0

<span>Friction slides or rolls one object to another</span>

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Cereal is an example of what type of matter?

Delvig [45]

Cereal is a heterogeneous mixture because it is composed of many different types of ingredients.

5 0

3 years ago

If 1.0 M HIM HI is placed into a closed container and the reaction is allowed to reach equilibrium at 25∘C∘C, what is the equili

sattari [20]

The given question is incomplete. The complete question is

If 1.0 M HI is placed into a closed container and the reaction is allowed to reach equilibrium at 25∘C∘C, what is the equilibrium concentration of H2 (g). Given the equilibrium constant is 62.

Answer: The equilibrium concentration of $H_2$ is 0.498 M

Explanation:

Initial concentration of $HI$ = 1.0 M

The given balanced equilibrium reaction is,

$2HI(g)\rightarrow H_2(g)+I_2(g)$

initial (1.0) M 0 0

At eqm (1.0-2x) M (x) M (x) M

The expression for equilibrium constant for this reaction will be,

$K_c=\frac{[H_2]\times [I_2]}{[HI]^2}$

Now put all the given values in this expression, we get :

$62=\frac{(x)^2}{1.0-2x}$

By solving we get :

$x=0.498M$

Thus the equilibrium concentration of $H_2$ is 0.498 M

6 0

4 years ago

Assuming all the NH3 dissolves and that the volume of the solution remains at 0.450 L , calculate the pH of the resulting soluti

Yanka [14]

Answer:

8.9357.

Explanation:

So, let us dive right into the solution to the above problem;

We have that the volume of the solution = 0.450 L.

The first thing to do is to determine the number of moles by using the formula below:

Pressure × volume = number of moles × gas constant × temperature.

Therefore, making the number of moles the subject of the formula we have;

Number of moles = (pressure × volume)/ has constant × temperature.

Number of moles of NH3=( 735 × 7.50 )/ 62.4 × 295 = 0.2995 moles.

The number of moles of HCl =

0.450 × 0.450 = 0.2025 moles.

Molarity of HCl = 0.2025 moles/ 0.450 L = 0.45M.

The molarity of {OH^-} = (0.2995 moles - 0.2025 moles) /0.450 = 0.097/0.450 = 0.2156 M.

Therefore, kb = 1.8 × 10^-5 = [ 0.450] [OH^-] / [ 0.2156 M] = 0.000008624.

[OH^-] = 0.000008624.

Hence, pOH = 5.0643.

pH = 14 - 5.0643 = 8.9357.

6 0

3 years ago

The average rate of a reaction is a good approximation of an instantaneous rate when?

Lunna [17]

The average rate of a reaction is a good approximation of an instantaneous rate when the concentration is measured during relatively brief time intervals.

At any point during such a little period, the average rate will be extremely near to the instantaneous rate. The average rate will differ from the instantaneous rates inside the period more when time intervals are longer.

The concentration change during a chosen time period is the average rate. When you take the measurements makes a difference.

The rate at a specific moment is known as the instantaneous rate. Finding the slope of the tangent to the concentration vs. time curve at that point yields the answer.

Learn more about comparison between average and instantaneous rate here brainly.com/question/17960561

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4 0

2 years ago

ANSWER ASAP! PLEASE!

Eva8 [605]

Evaporation and straining.and idk the other two

4 0

3 years ago