What is the speed of a wave with a frequency of 2 Hz and a wavelength of 87m (subject is science) pls answer fast

A 251 ml sample of 0.45M HCl is added to 455 mL of distilled water. What is the molarity of the

Oksi-84 [34.3K]

We are given:

251 mL sample of 0.45M HCl added to 455 mL distilled water

Whack a mole! (finding the number of moles):

We know that in order to find molarity, we use the formula:

Molarity = number of moles / Volume (in L)

so, number of moles is:

Number of moles = Molarity * Volume(in L)

now let's plug the values for the HCl solution to find the number of moles

Number of moles = 0.45M * 0.251 L

Number of moles = 0.113 moles

Time to concentrate (finding the final concentration):

Total final volume = 251 mL + 455 mL = 706 mL = 0.706 L

Number of moles of HCl = 0.113 moles

Molarity = Number of moles / Volume (in L)

Molarity = 0.113 / 0.706

Molarity = 0.16 M

___________________________________________________________

BONUS METHOD TIME!!!

We know the relation:

M1 * V1 = M2 * V2

where M1 and M2 are the initial and final molarities and V1 and V2 are initial and final volumes respectively

notice that I didn't mention that the volume has to be in Liters, that's because of the units being concerned with both sides of the equation, say I have the volume in mL and want to convert both these volumes to L, I would divide both sides by 1000, which would NOT change the overall value

Now, plugging values in this equation

(0.45) * (251) = (251 + 455)* (M2)

112.95 = (706)(M2)

M2 = 112.97/706 [dividing both sides by 706]

M2 = 0.16 Molar

8 0

2 years ago

Which one of Newton's Laws fits this statement: More mass means more force needed to accelerate?

ivolga24 [154]

Answer:

Newton's Second Law

Explanation:

Newton's second law basically states that the acceleration of a body which is produced by a net force is directly proportional to the magnitude of net force applied in the same direction.

This tells us that

F is directly proportional to a

⇒ F= ma

So we can also state from the above equation, that when we have more mass, we need more net force to accelerate it. Here, we are keeping the acceleration constant so we can surely say that force and mass varies directly.

Therefore, we have made good use of Newton's Second Law of motion to arrive at this conclusion.

4 0

3 years ago

Which statement best describes the organelles in a cell

Bas_tet [7]

Answer:

(2) Organelles must work together and their

activities must be coordinated

Explanation:

Organelles are usually located in cells. They are saddled with the role of performing specific functions in the cells for the overall functioning of life. In eukaryotic cells, the organelles are membrane bounded but in prokaryotic or primitive cells such is not the case.

Examples of cell organelles are ribosome, food vacuole, nucleus e.t.c. Just like organs in the body, organelles must work together in order to enhance life.

5 0

2 years ago

A spinning turbine can generate electricity only in the form of a/an _______ current.

Tom [10]

Answer:

The correct answer is - alternating and direct, in order.

Explanation:

Alternating current is is type of electric current that is characterized by the direction of the flow of electrons in continuously switches its directs in opposite manner at regular cycles. While direct current or DC is flow of the electrons that move from starting to end in one direction.

Spinning turbines always leads to the alternating electric current while only solar energy produces the direct current with the help of the solar panels.

Thus, the correct answer is - alternating and direct, in order.

3 0

3 years ago

An element X forms a compound XH 3 with hydrogen. Another element Y forms a compound YX 2 with X. Given that the valency of hydr

Marina CMI [18]

X $H_{3}$
H has a positive 1 charge. This means that having 3H = +3. This is a neutral compound so x= -3 because X+3H= 0

Y $X_{2}$ is also neutral so 2X+Y= 0
we know X=-3 So, 2(-3)+Y=0
-6+y=0
Y=+6 charge

Answer: The valency of X is -3. The valency of Y is 6

7 0

3 years ago

What is the speed of a wave with a frequency of 2 Hz and a wavelength of 87m￼ (subject is science) pls answer fast

What is the speed of a wave with a frequency of 2 Hz and a wavelength of 87m (subject is science) pls answer fast