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2 years ago

How is an echo formed?

Chemistry

2 answers:

mojhsa [17]2 years ago

5 0

Answer: B

Explanation: echos cannot be made from light waves so C and D are out, and sound waves cannot travel into a surface. Also echos is sound waves bouncing that’s why in an empty room without furniture there’s an echo.

Finger [1]2 years ago

3 0

Answer:

It is none. Echo is formed when sound waves hit a hard surface.

Explanation:

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Determine the kinds of intermolecular forces that are present in each element or compound. you may want to reference ( pages 466

Alla [95]

<span>Majorly there are four types of inter molecular forces: Permanent dipole (like in HCl or NaCl) Ion dipole and Ion induced dipole Hydrogen bonding Van der Waals forces (Keesom, Debye, and London dispersion force)</span>

5 0

3 years ago

Material of density of 762 kg/m3 occupies a container

konstantin123 [22]

Answer:

The answer is

Explanation:

The mass of a substance when given the density and volume can be found by using the formula

<h3>mass = Density × volume</h3>

From the question

density = 762 kg/m³

We must first convert the volume from cm³ to m³

$1 \: {cm}^{3} = 1 \times {10}^{ - 6} {m}^{3}$

So 99 cm³ will be

$9.9 \times {10 }^{ - 5} \: \: {m}^{3}$

So the mass of the material is

$mass = 762 \times 9.9 \times {10}^{ - 5} \\ = 0.075438$

We have the final answer as

Hope this helps you

4 0

4 years ago

Read 2 more answers

What are the hazards, if any of the reactants AgNO3, and K2CrO4?

Mandarinka [93]

This is what i wrote in my notebook: (for AgNO3)
<span>Health Hazards Acute and Chronic: ACUTE:
INHALATION - MAY CAUSE SEVERE IRRITATION TO MUCOUS MEMBRANES.
SKIN - MAY CAUSE SEVERE IRRITATION.
EYE - MAY CAUSE SEVERE IRRITATION.
CHRONIC: INHALATION, SKIN & INGESTION - MAY CAUSE ARSYRIA. Explanation of Carcinogenicity:THIS COMPOUND CONTAINS NO INGREDIENTS AT CONCENTRATIONS OF 0.1% OR GREATER THAT ARE CARCINOGENS OR SUSPECT CARCINOGENS.

</span><em><u>AgNO3 + K2CrO4 = Ag2CrO4 + KNO3</u></em>

3 0

3 years ago

Which of the following is a molecule but

Oksana_A [137]

Answer:

CO2

Explanation:

All of the other options are elements found on the periodic table but Carbon Dioxide are two elements.

5 0

3 years ago

Two linear hydrocarbons, Hexane (C6H14) and Heptane (C7H16), form pretty much an ideal solution at any composition. A solution i

Anettt [7]

Answer:

$y_{C_6H_{14}}=0.92$

Explanation:

Hello,

At first, we compute liquid-phase molar fractions:

$n_{C_6H_{14}}=463.96 g*\frac{1mol}{86g} =5.3949molC_6H_{14}\\n_{C_7H_{16}}=667.71 g*\frac{1mol}{100g} =6.6771molC_7H_{16}\\x_{C_6H_{14}}=\frac{5.3949}{5.3949+6.6771} =0.447\\x_{C_7H_{16}}=1-x_{C_6H_{14}}=0.553$

Now, by means of the fugacity concept, for hexane, for instance, we have:

$f_{C_6H_{14}}^V=f_{C_6H_{14}}^L\\y_{C_6H_{14}}p_T=x_{C_6H_{14}}p_{C_6H_{14}}$

In this manner, at 25 °C the vapor pressure of hexane and heptane are 0.198946 atm and 0.013912 atm repectively, thus, the total pressure is:

$p_T=x_{C_6H_{14}}p_{C_6H_{14}}+x_{C_7H_{16}}p_{C_7H_{16}}\\p_T=0.447*0.198946 atm +0.553*0.013912 atm=0.096622atm$

Finally, from the hexane's fugacity equation, we find its mole fraction in the vapour as:

$y_{C_6H_{14}}=\frac{x_{C_6H_{14}}p_{C_6H_{14}}}{p_T}=\frac{0.447*0.198946 atm}{0.096622atm} \\y_{C_6H_{14}}=0.92$

Best regards.

3 0

3 years ago

Read 2 more answers