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4 years ago

How many atoms are in 0.750 moles of zinc?

1 answer:

4 0

1 mole Zn ---------- 6.02 x 10²³ atoms
0.750 moles Zn ----- ?

atoms = 0.750 * ( 6.02 x 10²³ / 1 )

= 4.515 x 10²³ atoms

hope this helps!

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Which of the following correctly represents 148 million kilometers in scientific notation?

ryzh [129]

The answer is 1.48 x 10^8. This is because 148 million is represented as 148 000 000 and it takes 8 decimal places to make it 1.48. Hope this helps!

5 0

3 years ago

What is the concentration, in grams per liter, of a solution prepared by dissolving 0.00040 mol HCl in 2.2 L H2O? Assume that th

Zolol [24]

Answer:

0.00663 grams/liter

Explanation:

HCl is a mineral acid with a molar mass of 36.46 g/mol.

No. of moles= mass/RMM

Making mass the subject of the formula:

Mass=Number of moles × RMM

Therefore 0.00040 mol HCl has a mass of:

0.00040 mol × 36.46 g/ mol

=0.01458 grams.

0.01458 grams are in 2.2 liters, Therefore 1 liter will have

0.01458 grams/2.2 liters= 0.00663 grams

concentration= 0.00663 grams/liter

4 0

3 years ago

Read 2 more answers

A gas has a pressure of 7.01 atm at 227°C. What will its temperature be if the pressure is increased to 12.1 atm and volume is h

kirill [66]

Answer:

The temperature of the gas will be 590.05 C.

Explanation:

Gay-Lussac's law can be expressed mathematically as follows:

$\frac{P}{T} =k$

Where P= Pressure, T = temperature, K = Constant

This law indicates that the ratio between pressure and temperature is constant.

This law indicates that, as long as the volume of the container containing the gas is constant, as the temperature increases, the gas molecules move faster. Then the number of shocks against the walls increases, that is, the pressure increases. That is, the gas pressure is directly proportional to its temperature.

In short, when there is a constant volume, as the temperature increases, the gas pressure increases. And when the temperature decreases, gas pressure decreases.

It is desired to study two different states, an initial state and an final state. You have a gas that is at a pressure P1 and at a temperature T1 at the beginning of the experiment. When the temperature varies to a new T2 value, then the pressure will change to P2, and the following will be true:

$\frac{P1}{T1} =\frac{P2}{T2}$

In this case:

P1= 7.01 atm
T1= 227 C= 500 K (being 0 C= 273 K)
P2= 12.1 atm
T2= ?

Replacing:

$\frac{7.01 atm}{500 K} =\frac{12.1 atm}{T2}$

Solving:

$T2=12.1 atm*\frac{500 K}{7.01 atm}$

T2= 863.05 K= 590.05 C

The temperature of the gas will be 590.05 C.

6 0

3 years ago

Complete the following equation of nuclear transmutation.

LiRa [457]

Answer:

Option A. 1 0n

Explanation:

Details on how to balanced the equation for the reaction given in the question above can be found in the attached photo.

4 0

4 years ago

Explain the effects that different frequencies of electromagnetic radiation have when absorbed by matter.

Neko [114]

In order to answer this question we might first want to think about what is electromagnetic radiation. In essence it’s light, just some of the wavelengths are too long or too short for us to see.

We can think about it as two oscillating sinusoidal (goes up and down) waves, one is electric, the other is magnetic.

Because we’re dealing in waves, that means we can calculate their frequency, wavelength, amplitude (brightness) and period.

To calculate it we can use E=hc/lambda
Where E = jewels of energy
h = Planck’s constant
c = speed of light
Lambda = wavelength

It doesn’t really matter for this question what those things mean, just note that it takes more energy to have a shorter wavelength, or less energy to have a longer wavelength.

So now we can answer the question. Light of a longer wavelength has less energy than that of a shorter wavelength. So, when long wavelengths are absorbed by matter (atoms) they will give those atoms less energy. So, either it will pass through the object entirely or it will make the atoms vibrate a little bit more than they already are and we call that thermal energy, or heat.

If high energy wavelengths are passing through matter then they will be giving those atoms a lot of energy, sometimes even ionizing the atoms.
Which, if you’re a living thing can be very bad for your cells.

I hope that helps.

8 0

4 years ago