The total amount of energy in the universe is...

A sample of 0.2140 g of an unknown monoprotic acid was dissolved in 25.0 mL of water and titrated with 0.0950MNaOH. The acid req

bezimeni [28]

in a monoprotic acid , its capable of dissociating 1 H⁺ ion . The base used is NaOH which is capable of giving out 1 OH⁻ ion.

Therefore both base and acid react in a 1:1 molar ratio, that means for each 1 mol of monoprotic acid there is , it requires 1 mol of NaOH to be neutralised.

So at equivalence point the number of acid moles present should react with an equal number of NaOH moles to be neutralised

number of NaOH moles added - concentration x volume

number of NaOH moles - 0.0950 mol/dm³ x 27.4 x 10⁻³ dm³ = 0.00260 mol

since molar ratio of NaOH to Acid is 1:1

number of acid moles present is also - 0.00260 mol

mass of acid added - 0.2140 g

we can find molar mass using following equation

molar mass = mass / number of moles

molar mass = 0.2140 g / 0.00260 mol = 82.3 g/mol

therefore molar mass of monoprotic acid is 82.3 g/mol

8 0

4 years ago

How does the scientific meaning of the words work, energy, force and efficiency compare to their every day meaning? State the si

Gelneren [198K]

Answer:

Force

If you're taking classical physics, simply stated, a force is a push or a pull of some sort. But there is one other very important thing to understand about Force. A true Force is always an interaction (at least from a classical perspective). That means that forces always come in pairs. This is stated in Newton's Third Law (equal and opposite forces). Every action must have a reaction. This is required for all true forces. Another consequence of this is that force is a vector, meaning it has a magnitude and a direction. The action and reaction will always be opposite in direction.

A lot of people will say F=ma. This is true. However, it is important to keep in mind that this definition is a calculational tool. It is more precise to say the Sum of all forces=ma. The point is that ma is not a force. Forces are things like weight, tension, normal, friction, gravity, electrostatic, magnetic, and various other applied forces. The sum of forces on an object equals the product of its mass times its acceleration.

It is important to keep in mind that the force is on the object that accelerates. Another way to state this is that objects cannot accelerate themselves. You cannot push yourself back (or forwards). But if you push a heavy object like a desk forwards, then the desk can push you back.

Energy

There are many kinds of energy. There are two important things to know.

Energy is the ability to do work. It doesn't mean work is being done, but that work can be done. (So you can see there is an intimate relationship between work and energy).

Energy is conserved. That means the total amount of energy is always constant. If the energy is a system changes somehow, that means some work was done in order to move the energy from one system to another.

Energy is also a scalar (given that Work is a scalar).

6 0

2 years ago

Brody is barbecuing hamburgers on the grill. He notices that the coals are ready for cooking because he feels the warmth of the

hodyreva [135]

Answer:

i think the answer is infrared

8 0

3 years ago

A flock of ducks is trying to migrate south for the winter, but they keep being blown off course by a wind blowing from the west

Minchanka [31]

The ducks' flight path as observed by someone standing on the ground is the sum of the wind velocity and the ducks' velocity relative to the wind:

ducks (relative to wind) + wind (relative to Earth) = ducks (relative to Earth)

or equivalently,

$\vec v_{D/W}+\vec v_{W/E}=\vec v_{D/E}$

(see the attached graphic)

We have

ducks (relative to wind) = 7.0 m/s in some direction θ relative to the positive horizontal direction, or

$\vec v_{D/W}=\left(7.0\dfrac{\rm m}{\rm s}\right)(\cos\theta\,\vec\imath+\sin\theta\,\vec\jmath)$

wind (relative to Earth) = 5.0 m/s due East, or

$\vec v_{W/E}=\left(5.0\dfrac{\rm m}{\rm s}\right)(\cos0^\circ\,\vec\imath+\sin0^\circ\,\vec\jmath)$

ducks (relative to earth) = some speed v due South, or

$\vec v_{D/E}=v(\cos270^\circ\,\vec\imath+\sin270^\circ\,\vec\jmath)$

Then by setting components equal, we have

$\left(7.0\dfrac{\rm m}{\rm s}\right)\cos\theta+5.0\dfrac{\rm m}{\rm s}=0$

$\left(7.0\dfrac{\rm m}{\rm s}\right)\sin\theta=-v$

We only care about the direction for this question, which we get from the first equation:

$\left(7.0\dfrac{\rm m}{\rm s}\right)\cos\theta=-5.0\dfrac{\rm m}{\rm s}$

$\cos\theta=-\dfrac57$

$\theta=\cos^{-1}\left(-\dfrac57\right)\text{ OR }\theta=360^\circ-\cos^{-1}\left(-\dfrac57\right)$

or approximately 136º or 224º.

Only one of these directions must be correct. Choosing between them is a matter of picking the one that satisfies both equations. We want

$\left(7.0\dfrac{\rm m}{\rm s}\right)\sin\theta=-v$

which means θ must be between 180º and 360º (since angles in this range have negative sine).

So the ducks must fly (relative to the air) in a direction 224º relative to the positive horizontal direction, or about 44º South of West.

8 0

3 years ago

On which date does the antarctic circle have 24 hours of daylight

Airida [17]

Answer:

21st of December

Explanation:

In the northern hemisphere there occurs winter solstice on 21st of December. During this time, the tilt of the earth in the northern hemisphere is away from the sun. So the places near and at Antarctica, there will be sunlight for about 24 hours and the sun does not set on this particular day.

And, on the other hand, the places near the Arctic circle experiences darkness for about 24 hours and the sun does not rise on this specific day.

6 0

3 years ago

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