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4 years ago

A comet takes 4 hours to cruise 200,000 kilometers through the Solar System. Why can't we determine the velocity of the comet?

Chemistry

2 answers:

dolphi86 [110]4 years ago

7 0

We don't know the comet's direction.

please mark brainliest.

Vikentia [17]4 years ago

5 0

Answer:

The correct answer is option b: We don't know the comet's direction.

Explanation:

Hello!

Let's solve this!

To calculate the speed, we need to know the initial position and the final position.

We also need the initial time and the final time.

In this case we have the distance traveled, but not from where and where the comet came from.

After the analysis, the correct answer is option b: We don't know the comet's direction.

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Calculate the energy E of a sample of 3.50 mol of ideal oxygen gas (O2) molecules at a temperature of 310 K. Assume that the mol

love history [14]

Answer:

13.53 kJ

Explanation:

The energy of a gas can be calculated by the equation:

E = (3/2)*n*R*T

Where n is the number of moles, R is the gas constant (8.314 J/mol.K), and T is the temperature.

E = (3/2)*3.5*8.314*310

E = 13,531.035 J

E = 13.53 kJ

7 0

3 years ago

A 1.00 g sample of a metal X (that is known to form X ions in solution) was added to 127.9 mL of 0.5000 M sulfuric acid. After a

Semenov [28]

<u>Answer:</u> The metal having molar mass equal to 26.95 g/mol is Aluminium

<u>Explanation:</u>

To calculate the number of moles for given molarity, we use the equation:

$\text{Molarity of the solution}=\frac{\text{Moles of solute}}{\text{Volume of solution (in L)}}$ .....(1)

Molarity of NaOH solution = 0.5000 M

Volume of solution = 0.03340 L

Putting values in equation 1, we get:

$0.5000M=\frac{\text{Moles of NaOH}}{0.03340L}\\\\\text{Moles of NaOH}=(0.5000mol/L\times 0.03340L)=0.01670mol$

The chemical equation for the reaction of NaOH and sulfuric acid follows:

$2NaOH+H_2SO_4\rightarrow Na_2SO_4+H_2O$

By Stoichiometry of the reaction:

2 moles of NaOH reacts with 1 mole of sulfuric acid

So, 0.01670 moles of NaOH will react with = $\frac{1}{2}\times 0.01670=0.00835mol$ of sulfuric acid

Excess moles of sulfuric acid = 0.00835 moles

Calculating the moles of sulfuric acid by using equation 1, we get:

Molarity of sulfuric acid solution = 0.5000 M

Volume of solution = 127.9 mL = 0.1279 L (Conversion factor: 1 L = 1000 mL)

Putting values in equation 1, we get:

$0.5000M=\frac{\text{Moles of }H_2SO_4}{0.1279L}\\\\\text{Moles of }H_2SO_4=(0.5000mol/L\times 0.1279L)=0.06395mol$

Number of moles of sulfuric acid reacted = 0.06395 - 0.00835 = 0.0556 moles

The chemical equation for the reaction of metal (forming $M^{3+}$ ion) and sulfuric acid follows:

$2X+3H_2SO_4\rightarrow X_2(SO_4)_3+3H_2$

By Stoichiometry of the reaction:

3 moles of sulfuric acid reacts with 2 moles of metal

So, 0.0556 moles of sulfuric acid will react with = $\frac{2}{3}\times 0.0556=0.0371mol$ of metal

To calculate the molar mass of metal for given number of moles, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$

Mass of metal = 1.00 g

Moles of metal = 0.0371 moles

Putting values in above equation, we get:

$0.0371mol=\frac{1.00g}{\text{Molar mass of metal}}\\\\\text{Molar mass of metal}=\frac{1.00g}{0.0371mol}=26.95g/mol$

Hence, the metal having molar mass equal to 26.95 g/mol is Aluminium

6 0

3 years ago

Prove that circle p and circle q are similar.

abruzzese [7]

All circles are similar.

8 0

3 years ago

What quantity can be calculated for a solid compound, given only the formula of the compound and the periodic table of elements

gavmur [86]

When you have both of these ( The periodic table of elements and the formula of your compound) you are able to calculate the R.M.M ( Relative atomic mass) of that compound.
For example the formula of a NaCl ( Table salt ) has the elemnt Na and Cl.
We look at the atomic mass of both of these compounds
Na - 23
Cl - 35.5
R.M.M = 23 +35.5 = 58.5
Hope this helps :).

6 0

3 years ago

In terms of the atmosphere, which of the following best describes the oxygen that is present?

Viktor [21]

The atmosphere is considered homogeneous. It isn’t exactly on the smallest scales but that doesn’t matter. Homogenous means the composition will be the same in any sample taken from the substance. And clearly, the atmosphere is mostly gas. So the last answer is right

6 0

3 years ago