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mihalych1998 [28]

2 years ago

7

On a cool morning, Uyen’s breath can form a cloud when she breathes out. Which changes of state are most responsible for Uyen se

eing her breath in this way?
melting
condensation
deposition
sublimation

2 answers:

Dima020 [189]2 years ago

8 0

Condensation because condensation is a process of freezing

sergiy2304 [10]2 years ago

7 0

The 2nd one is the correct answer

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A typical adult human body contains approximately 2.500 L of blood plasma. How many grams of blood plasma are in the typical adu

kirill115 [55]

Answer:

$m=2.575g$

Explanation:

Hello,

In this case, since the density is defined as the ratio of the mass and volume:

$\rho =\frac{m}{V}$

We can compute the mass of blood as follows:

$m=\rho *V=1.03g/L*2.500L\\\\m=2.575g$

Best regards.

7 0

2 years ago

A battery has an electrical ______________ energy

aleksley [76]

Answer:

Electrical Energy

Explanation:

There are a variety of chemical and mechanical devices that are called batteries, although they operate on different physical principles. A battery for the purposes of this explanation will be a device that can store energy in a chemical form and convert that stored chemical energy into electrical energy when needed.

5 0

2 years ago

(Please answer ASAP) Describe in your own words A.) what does Inert mean? B.) why are noble gases Inert (include an explanation

Alex_Xolod [135]

Inert means unreactive in nature or un reactive in there normal or natural state
and noble gas has there outermost shell electron filled up they complete there duplet or oclet valency state that why there inert in there natural state

4 0

3 years ago

Enter your answer in the provided box. From the data below, calculate the total heat (in J) needed to convert 0.304 mol of gaseo

diamong [38]

Answer:

-35,281.5 J

Explanation:

To convert the gaseous ethanol to liquid ethanol, three steps will occur. First, it will lose heat and the temperature will decrease until its boiling point, so from 300.0°C to 78.5°C. Thus, more heat will be lost, but now, with the temperature constant, so the gas will be converted to liquid. And then, the liquid will lose heat to decrease the temperature from 78.5°C to 25.0°C.

The total heat loss is the sum of the heats of each step. Because the heat is being removed from the system, it's negative. The first and last step occurs with a change in temperature, and so the heat is calculated by:

Q = m*c*ΔT

Where m is the mass, c is the specific heat of the gas (first step) or liquid (last step), and ΔT the temperature variation (final - initial). The mass of ethanol is the molar mass 46.07 g/mol multiplied by the number of moles, so:

m = 46.07 * 0.304 = 14.00 g

The second step occurs without a change in temperature, and the heat is then:

Q = -n*ΔH°vap

Where n is the number of moles, ΔH°vap is the heat of vaporization, and the minus signal indicates that the heat is being lost. Then, the heat of each step is:

Q1 = 14.00*1.43*(78.5 - 300,0) = -4434.43 J

Q2 = -0.304*40.5 = -12.312 kJ = -12312 J

Q3 = 14.00*2.45*(25.0 - 78.5) = -1835.05 J

Q = Q1 + Q2 + Q3

Q = -35,281.5 J

5 0

3 years ago

Which of the following statements is incorrect? A. Molecular mass is expressed in atomic mass units. B. Formula mass compares th

n200080 [17]

Answer:

The incorrect statement is the choice <em>C. Atomic mass has units of grams per atom.</em>

Explanation:

<u>1) Choice A.</u><em><u> Molecular mass is expressed in atomic mass units</u></em><u>.</u>

Correct. Atomic mass units (a.m.u) is the standard unit used to express the mass of the atoms and the molecules.

Since, one atom, molecule, or formula unit is a tiny amount of material, it has a ver, very low mass, and the unit mass of a molecule is referred to one mole (6.022 × 10²³ units).

<u>2) Choice B. </u><em><u>Formula mass compares the mass of one formula unit of a substance to the mass of one atom of carbon-12</u></em><u>.</u>

Correct. The masses of atoms and compounds are referred to a standard. Such standard is the carbon-12 atom. This is, the cabon-12 atom was selected as the standard and its exact mass is 12 a.m.u.

<u>3) Choice C. </u><em><u>Atomic mass has units of grams per atom.</u></em><u> </u>

Incorrect. Atomic mass is the mass of the atoms, but, since, the mass of one atom is so small, the atomic mass is referred to one mole. Hence, the atomic mass has units of grams per mole.

<u>4) Choice D. </u><em><u>Both molecular mass and formula mass use carbon-12 as a reference standard.</u></em>

Correct. As stated when explaining the option B, the mass of atoms, molecules, and formula units are referred to carbon-12 standard.

<u>5) Choice E. S</u><em><u>odium chloride, an ionic compound, is said to have a formula weight, but not a molecular weight.</u></em>

Correct. The reason is that ionic compounds form large structures (crystals) and, since there is not such thing as one molecule of them, they are said to have formula weight (or mass) but not a molecular weight.

The name molecules is reserved for covalent compounds, where you can formally identify molecules. E.g. Water is a molecular compound, and each molecule has molecular formula H₂O, whose mass is the molecular mass.

7 0

3 years ago