How many molecules of ethane ( C2H6) are present in 0.197g of C2H6?

Mammals and plants do not belong in the same domain. Fact: Evidence:

Zepler [3.9K]

False

Fact: Mammals and plants belong to the same domain, the Eukarya domain.

Evidence :All the organisms that possess a eukaryotic cell, plants, animals, protists, and fungi are in the Eukarya domain.

3 0

3 years ago

The equilibrium constant for the reaction of carbon monoxide with water is 1.845. if 1.00 mol of each reactant is placed in a 2.

SpyIntel [72]

[CO] = 1 mol / 2L = 0.5 M

[
According to the equation:

and by using the ICE table:

CO(g) + H2O(g) ↔ CO2(g) + H2(g)

initial 0.5 0.5 0 0

change -X -X +X +X

Equ (0.5-X) (0.5-X) X X

when Kc = X^2 * (0.5-X)^2

by substitution:

1.845 = X^2 * (0.5-X)^2 by solving for X

∴X = 0.26

∴ [CO2] = X = 0.26

4 0

3 years ago

a 125 g chunk of aluminum at 182 degrees Celsius was added to a bucket filled with 365 g of water at 22.0 degrees Celsius. Ignor

Diano4ka-milaya [45]

<h3>Answer:</h3>

32.98°C

<h3>Explanation:</h3>

We are given the following;

Mass of Aluminium as 125 g

Initial temperature of Aluminium as 182°C

Mass of water as 265 g

Initial temperature of water as 22°C

We are required to calculate the final temperature of the two compounds;

First, we need to know the specific heat capacity of each;

Specific heat capacity of Aluminium is 0.9 J/g°C

Specific heat capacity of water is 4.184 J/g°C

<h3>Step 1: Calculate the Quantity of heat gained by water.</h3>

Assuming the final temperature is X°C

we know, Q = mcΔT

Change in temperature, ΔT = (X-22)°C

therefore;

Q = 365 g × 4.184 J/g°C × (X-22)°C

= (1527.16X-33,597.52) Joules

<h3>Step 2: Calculate the quantity of heat released by Aluminium </h3>

Using the final temperature, X°C

Change in temperature, ΔT = -(X°- 182°)C (negative because heat was lost)

Therefore;

Q = 125 g × 0.90 J/g°C × (182°-X°)C

= (20,475- 112.5X) Joules

<h3>Step 3: Calculating the final temperature</h3>

We need to know that the heat released by aluminium is equal to heat absorbed by water.

Therefore;

(20,475- 112.5X) Joules = (1527.16X-33,597.52) Joules

Combining the like terms;

1639.66X = 54072.52

X = 32.978°C

= 32.98°C

Therefore, the final temperature of the two compounds will be 32.98°C

7 0

3 years ago

The wavelength of a wave can be found by measuring how high the wave is measuring how many waves pass a point in a second measur

Liono4ka [1.6K]

Now that you know something about the properties of the two main types of waves (Lesson 43), we need to make sure that you can look at individual characteristics that waves can have.

Not all waves are created equal!You need to be able to see the specific “faces” that each wave can have, based on three important characteristics: frequency, wavelength, and amplitude.Frequency

When we first started looking at SHM we defined period as the amount of time it takes for one cycle to complete... seconds per cycle

Frequency is the same sort of idea, except we’re just going to flip things around.Frequency is a measurement of how many cycles can happen in a certain amount of time… cycles per second.If a motor is running so that it completes 50 revolutions in one second, I would say that it has a frequency of 50 Hertz.Hertz is the unit of frequency, and just means how many cycles per second.It is abbreviated as Hz.It is named after Heinrich Hertz, one member of the Hertz family that made many important contributions to physics.In formulas frequency appears as an "f".

Since frequency and period are exact inverses of each other, there is a very basic pair of formulas you can use to calculate one if you know the other…

It is very easy to do these calculations on calculators using the x-1 button.

Example 1: The period of a pendulum is 4.5s. Determine the frequency of this pendulum.

The period means that it will take 4.5 seconds for the pendulum to swing back and forth once. So, I expect that my frequency will be a decimal, since it will complete a fraction of a swing per second.Wavelength

Wavelength is a property of a wave that most people (once they know what to look for) can spot quickly and easily, and use it as a way of telling waves apart. Look at the following diagram...

Figure 1Any of the parts of the wave that are pointing up like mountains are called crests. Any part that is sloping down like a valley is a trough.Wavelength is defined as the distance from a particular height on the wave to the next spot on the wave where it is at the same height and going in the same direction.Usually it is measured in metres, just like any length.There isn’t a special spot you have to start on a wave to measure wavelength, just make sure you are back to the same height going in the same direction. Most people do like to measure from one crest to the next crest (or trough to trough), just because they are easy to spot.Figure 2

On a longitudinal wave, the wavelength is measured as the distance between the middles of two compressions, or the middles of two expansions.

Figure 3

This leads us to one of the most important formulas you will use when studying waves.

Frequency tells us how many waves are passing a point per second, the inverse of time.Wavelength tells us the length of those waves in metres, almost like a displacement.If we multiply these two together, we are really multiplying 1/s and m… which gives us m/s, the velocity of the wave!

v = velocity of the wave (m/s)
f = frequency (Hz)
λ = wavelength (m)

Example 2: A wave is measured to have a frequency of 60Hz. If its wavelength is 24cm, determine how fast it is moving.

Example 3: The speed of light is always 3.00e8 m/s. Determine the frequency of red light which has a wavelength of 700nm.

Be careful when changing the 700nm into metres. Some people get really caught up with changing it into regular scientific notation with only one digit before the decimal. Why bother? It's only being used in a calculation. You’ll probably just make a mistake changing the power of 10, so just substitute in the power for the prefix and leave everything else alone…700 nm = 700 x 10-9 m since “nano” is 10-9.

Amplitude

Amplitude is a measure of how big the wave is.

Imagine a wave in the ocean. It could be a little ripple or a giant tsunami.What you are actually seeing are waves with different amplitudes.They might have the exact same frequency and wavelength, but the amplitudes of the waves can be very different.

The amplitude of a wave is measured as:

the height from the equilibrium point to the highest point of a crest orthe depth from the equilibrium point to the lowest point of a troughFigure 4

When you measure the amplitude of a wave, you are really looking at the energy of the wave.

It takes more energy to make a bigger amplitude wave.Anytime you need to remember this, just think of a home stereo’s amplifier… it makes the amplitude of the waves bigger by using more electrical energy.

6 0

3 years ago

Hard water often contains dissolved Ca2+ and Mg2+ ions. One way to soften water is to add phosphates. The phosphate ion forms in

avanturin [10]

5.5×10−2M in calcium chloride and 8.0×10−2M in magnesium nitrate.
What mass of sodium phosphate must be added to 1.5L of this solution to completely eliminate the hard water ion

1) Content of Ca (2+) ions

Calcium chloride = CaCl2

Ionization equation: CaCl2 ---> Ca (2+) + 2 Cl (-)

=> Molar ratios: 1 mol of CaCl2 : 1 mol Ca(2+) : 2 mol Cl(-)

Calculate the number of moles of CaCl2 in 1.5 liters of 5.5 * 10^-2 M solution

M = n / V => n = M*V = 5.5 * 10^ -2 M * 1.5 l = 0.0825 mol CaCl2

=> 0.0825 mol Ca(2+)

2) Number of phosphate ions needed to react with 0.0825 mol Ca(2+)

formula of phospahte ion: PO4 (3-)

molar ratio: 2PO4(3-) + 3Ca(2+) = Ca3 (PO4)2

Proportion: 2 mol PO4(3-) / 3 mol Ca(2+) = x / 0.0825 mol Ca(2+)

=> x = 0.0825 coml Ca(2+) * 2 mol PO4(3-) / 3 mol Ca(2+) = 0.055 mol PO4(3-)

3) Content of Mg(2+) ions

Ionization equation: Mg (NO3)2 ----> Mg(2+) + 2 NO3 (-)

Molar ratios: 1 mol Mg(NO3)2 : 1 mol Mg(2+) + 2 mol NO3(-)

number of moles of Mg(NO3)2 in 1.5 liter of 8.0 * 10^-2 M solution

n = M * V = 8.0 * 10^ -2 M * 1.5 liter = 0.12 moles Mg(NO3)2

ions of Mg(2+) = 0.12 mol Mg(NO3)2 * 1 mol Mg(2+) / mol Mg(NO3)2 = 0.12 mol Mg(2+)

4) Number of phosphate ions needed to react with 0.12 mol Mg(2+)

2PO4(3-) + 3Mg(2+) = Mg3(PO4)2

=> 2 mol PO4(3-) / 3 mol Mg(2+) = x / 0.12 mol Mg(2+)

=> x = 0.12 * 2/3 mol PO4(3-) = 0.16 mol PO4(3-)

5) Total number of moles of PO4(3-)

0.055 mol + 0.16 mol = 0.215 mol

6) Sodium phosphate

Sodium phosphate = Na3(PO4)

Na3PO4 ---> 3Na(+) + PO4(3-)

=> 1 mol Na3PO4 : 1 mol PO4(3-)

=> 0.215 mol PO4(3-) : 0.215 mol Na3PO4

mass in grams = number of moles * molar mass

molar mass of Na3 PO4 = 3*23 g/mol + 31 g/mol + 4*16 g/mol = 164 g/mol

=> mass in grams = 0.215 mol * 164 g/mol = 35.26 g

Answer: 35.26 g of sodium phosphate

5 0

3 years ago