I exercise

An empty plastic bottle is sealed in a cool room and then moved to a very hot room. What can best be stated about the air pressu

mel-nik [20]

<span>A fast moving stream of air has a lower air pressure than a slower air stream. As the stream of air moved over the top of the paper, the air pressure over the paper dropped. The air pressure underneath the paper stayed the same. The greater air pressure underneath lifted the paper strip and it rose. The idea that a moving air stream has lower air pressure than air that is not moving is called “Bernoulli’s Principle”.

</span>The force of the moving air underneath the balloon was enough to hold it up. The weight added by the paper clip prevents the balloon from going too high. But that is only part of the story. The balloon stays inside the moving stream of air because the pressure inside is the air stream is lower than the still air around it. As the balloon moves toward the still air outside of the air stream, the higher pressure of the still air forces the balloon back into the lower pressure of the air stream. Bernoulli’s Principle at work again!

6 0

3 years ago

Read 2 more answers

Since electrons ___ each other, electrons pairs will be as _____ apart as possible

ELEN [110]

We have to answer based on basic concept on electron.

The correct answer is: Since electrons repel each other, electrons pairs will be as far apart as possible.

We know, electrons are negatively charged particles and negatively charged particles repel to each other.

When electrons which are of similar charge repel each other, they go far apart from each other..

4 0

3 years ago

It takes 945. kJ/mol to break a nitrogen-nitrogen triple bond. Calculate the maximum wavelength of light for which a nitrogen-ni

kolezko [41]

Answer: 1.274 * 10^ -7 meter (same as 127.4 nanometers

Explanation:

It's given that the energy

required to break the N N triple bond is 945 * 10^3 joules per mole.

One mole contains 6.02 * 10^ 23 molecules, so the energy required per molecule

= 945 * 10^3 / 6.023 * 10^23, or 1.56 * 10^-18 joules.

Then we need a photon whose energy (E) is at least that amount.

The energy E of a photon is related to its frequency f by PLANCK'S EQUATUON,

E = hf,

where h is Planck's constant (6.625 * 10^-34 joule-sec)

and the wavelength w is inversely proportional to the frequency by w = c/f, where c is the speed of light, 2.998 * 10^8 meters per sec.

If h & c are both constants, their product hc is constant, so we can say E = hc/w,

or if we know E and want to find w, a little algebra gives: w = hc/E.

The product hc = 1.9875 * 10^-25 joule-meters,

so w = 1.9875 * 10^-25 / 1.56 * 10^-18, or 1.274 * 10^ -7 meter (same as 127.4 nanometers

6 0

3 years ago

A student collects 350 mL of a vapor at a temperature of 67°C. The atmospheric pressure at the time of collection is 0.900 atm.

Fed [463]

Answer:

Explanation:

This problem is very similar to the other that you put before, so, we'll use the same principle here.

The ideal gas equation: PV = nRT

Where:

P: pressure in atm

V: volume in L

T: Temperature in K.

n: moles

R: Gas constant (In this case, we'll use 0.082 L atm/K)

to get the molar mass of the gas, we need to know the moles, and with the mass, we can know the molar mass. However we can put the ideal gas expression with the molar mass in this way:

we know that n is mole so:

n = g/MM

If we put this in the idea gases expression we have:

PV = gRT/MM

Solving for MM we have:

MM = gRT/PV

Now, let's convert the temperature and volume to K and L respectively:

T = 67 + 273 = 340 K

V = 350 / 1000 = 0.35 L

Now all we have to do is put all the data into the expression:

MM = 0.79 * 0.082 * 340 / 0.9 * 0.35

MM = 22.0252 / 0.315 = 69.92 g/mol rounded 70 g/mol

Now, the closest answer of your options would be 72 g/mol. This could be easily explained because we do not use all the significant figures of all numbers, including the gas constant of R. However, all the work, calculations and procedure is correct and fine, and we only have a minimum range of 2 units.

6 0

3 years ago

Now they feel it is best to have you identify an unknown gas based on its properties. Suppose 0.508 g of a gas occupies a volume

pishuonlain [190]

Answer: Option (b) is the correct answer.

Explanation:

The given data is as follows.

mass = 0.508 g, Volume = 0.175 L

Temperature = (25 + 273) K = 298 K, P = 1 atm

As per the ideal gas law, PV = nRT.

where, n = no. of moles = $\frac{mass}{\text{molar mass}}$